Method and apparatus for transmitting or detecting a primary synchronization signal

ABSTRACT

A method and apparatus for transmitting or detecting primary synchronization signal. The receiver receives primary synchronization signal from a transmitter, and detects the sequence used in the received primary synchronization signal by using three root indexes. Here, the primary synchronization signal is generated by using a Zadoff-Chu sequence having one of the three root indexes. The three root indexes comprise a first index and a second index, and a sum of the first index and the second index corresponds to the length of the Zadoff-Chu sequence.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No.10-2007-0025175, filed on Mar. 14, 2007, Korean Patent Application No.10-2007-48353, filed on May 17, 2007, and Korean Patent Application No.10-2007-0057531, filed on Jun. 12, 2007, which are hereby incorporatedby reference as if fully set forth herein.

This application also claims the benefit of U.S. Provisional ApplicationSer. No. 60/870,786, filed on Dec. 19, 2006, U.S. ProvisionalApplication Ser. No. 60/884,399, filed on Jan. 10, 2007, U.S.Provisional Application Ser. No. 60/885,387, filed on Jan. 17, 2007,U.S. Provisional Application Ser. No. 60/888,304, filed on Feb. 5, 2007and U.S. Provisional Application Ser. No. 60/968,556, filed on Aug. 28,2007, the contents of which are hereby incorporated by reference hereinin their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a signal transmission/reception methodfor use in a communication system based on an orthogonal frequencydivision multiplexing (OFDM) scheme, and more particularly to a sequencegeneration method for allowing a reception end to effectively detect asequence used for a specific channel of mobile communication system, anda signal transmitting/receiving method using this sequence generationmethod.

Discussion of the Related Art

The OFDM, OFDMA, and SC-FDMA schemes for use in the present inventionwill hereinafter be described in detail.

In recent times, as the demand of high-speed data transmission rapidlyincreases, the OFDM scheme is more advantageous to this high-speedtransmission, so that the OFDM scheme is used as a transmission schemefor use in a variety of high-speed communication systems.

The OFDM (Orthogonal Frequency Division Multiplexing) scheme willhereinafter be described.

OFDM Scheme

According to the basic principles of the OFDM scheme, the OFDM schemedivides a high-rate data stream into many slow-rate data streams, andsimultaneously transmits the slow-rate data streams via multiplecarriers. Each of the carriers is called a sub-carrier.

In the OFDM scheme, the orthogonality exists between multiple carriers.Accordingly, although frequency components of the carrier are overlappedwith each other, the overlapped frequency components can be detected bya reception end.

More specifically, a high-rate data stream is converted to a parallellow-rate data stream by a serial to parallel (SP) converter. Theindividual sub-carriers are multiplied by the above parallel datastreams, the individual data streams are added to the multiplied result,and the added result is transmitted to the reception end.

On the other hand, the OFDMA scheme is a multiple access method forallowing the OFDM system to allocate the sub-carriers in a total band toeach of a plurality of users according to a transmission rate requiredby each user.

The conventional SC-FDMA (Single Carrier-FDMA) scheme will hereinafterbe described. This SC-FDMA scheme is also called a DFS-S-OFDM scheme.

SC-FDMA Scheme

The SC-FDMA scheme will hereinafter be described in detail. The SC-FDMAscheme mainly applied to an uplink performs the spreading based on theDFT matrix in a frequency domain before generating the OFDM signal,modulates the spreading result according to the conventional OFDMscheme, and transmits the modulated result.

Some variables are defined to explain the SC-FDMA scheme. “N” isindicative of the number of sub-carriers transmitting the OFDM signal.“Nb” is indicative of the number of sub-carriers for a predetermineduser. “F” is indicative of a Discrete Fourier Transform (DFT) matrix,“s” is indicative of a data symbol vector, “x” is indicative of a datadispersion vector in the frequency domain, and “y” is indicative of anOFDM symbol vector transmitted in the time domain.

Before the SC-FDMA scheme transmits the data symbol (s), the data symbol(s) is dispersed, as represented by the following equation 1:

x=F _(N) _(b) ×N _(b) ^(S)  [Equation 1]

In Equation 1, F_(N) _(b) ×N_(b) is indicative of a N_(b)-sized DFTmatrix to disperse the data symbol (s).

The sub-carrier mapping process is performed on the dispersed vector (x)according to a predetermined sub-carrier allocation technique. Themapping resultant signal is converted into a time-domain signal by theIDFT module, so that a desired signal to be transmitted to the receptionend is acquired. In this case, the transmission signal converted intotime-domain signal by to the transmission end can be represented by thefollowing equation 2:

y=F _(N×N) ⁻¹ x  [Equation 2]

In Equation 2, F_(N×N) ⁻¹ is indicative of the N-sized IDFT matrix forconverting a frequency-domain signal into a time-domain signal.

Then, a cyclic prefix is inserted into the signal (y) created by theabove-mentioned method, so that the resultant signal is transmitted.This method capable of generating the transmission signal andtransmitting the same to the reception end is called an SC-FDMA method.The size of the DFT matrix can be controlled in various ways toimplement a specific purpose.

The above-mentioned concepts have been disclosed on the basis of the DFTor IDFT operation. For the convenience of description, the followingdescription will be disclosed without discriminating between the DFT(Discrete Fourier Transform) scheme and the FFT (Fast Fourier Transform)scheme.

If the number of input values of the DFT operation is represented by themodular exponentiation of 2, it is well known to those skilled in theart that the FFT operation can be replaced with the DFT operation. Inthe following description, the FFT operation may also be considered tobe the DFT operation or other equivalent operation without any change.

Typically, the OFDM system forms a single frame using a plurality ofOFDM symbols, so that it transmits the single frame composed of severalOFDM symbols in frame units. The OFDM system firstly transmits thepreamble at intervals of several frames or each frame. In this case, thenumber of OFDM symbols of the preamble is different according to thesystem types.

For example, the IEEE 802.16 system based on the OFDMA scheme firstlytransmits the preamble composed of a single OFDM symbol at intervals ofeach downlink frame. The preamble is applied to a communicationterminal, so that the communication terminal can be synchronized withthe communication system, can search for a necessary cell, and canperform channel estimation.

FIG. 1 shows a downlink sub-frame structure of the IEEE 802.16 system.As shown in FIG. 1, the preamble composed of the single OFDM symbol islocated ahead of each frame, so that it is transmitted earlier than eachframe. The preamble is also used to search for the cell, perform thechannel estimation, and be synchronized in time and frequency.

FIG. 2 shows the set of the sub-carriers which transmit the preamblefrom the 0-th sector in the IEEE 802.16 system. Some parts of both sidesof a given bandwidth are used as the guard band. If the number ofsectors is 3, each sector inserts the sequence at intervals of 3sub-carriers, and “0” is inserted into the remaining sub-carriers, sothat the resultant sub-carriers are transmitted to a destination.

The conventional sequence for use in the preamble will hereinafter bedescribed. The sequence for use in the preamble is shown in thefollowing table 1.

TABLE 1 ID Index cell Sector Sequence (hexadecimal) 0 0 0A6F294537B285E1844677D133E4D53CCB1F18 2DE00489E53E6B6E77065C7EE7D0ADBEAF1 1 0 668321CBBE7F462E6C2A07E8BBDA2C7F7946D5F69E35AC8ACF7D64AB4A33C467001F3B2 2 2 01C75D30B2DF72CEC9117A0BD8EAF8E050246 1FC07456AC906ADE03E9B5AB5E1D3F98C6E. . . . . . . . . . . .

The sequence is defined by the sector number and the IDcell parametervalue. Each defined sequence is converted into a binary signal inascending numerical order, and the binary signal is mapped to thesub-carrier by the BPSK modulation.

In other words, the hexadecimal progression is converted into a binaryprogression (Wk), the binary progression (Wk) is mapped in the rangefrom the MSB (Most Significant Bit) to the LSB (Least Significant Bit).Namely, the value of 0 is mapped to another value of +1, and the valueof 1 is mapped to another value of −1. For example, the “Wk” value ofthe hexadecimal value “C12” at the 0-th segment having the index of 0 is“110000010010 . . . ”. The converted binary code value is −1, −1, +1,+1, +1, +1, +1, −1, +1, +1, −1, +1 . . . .

The sequence according to the conventional art maintains the correlationcharacteristics among various sequence types capable of being composedof binary codes. The sequence according to the conventional art canmaintain a low-level PAPR (Peak-to-Average Power Ratio) when data isconverted into another data of a time domain, and is found by thecomputer simulation. If the system structure is changed to another, orthe sequence is applied to another system, the conventional art mustsearch for a new sequence.

Recently, there is proposed a new sequence for use in the 3GPP LTE(3^(rd) Generation Partnership Project Long Term Evolution hereinafter“LTE”) technology, and a detailed description thereof will hereinafterbe described.

A variety of sequences have been proposed for the LTE system. Thesequences for use in the LTE system will hereinafter be described.

In order to allow the terminal to communicate with the Node-B (i.e.,base station), the terminal must be synchronized with the Node-B over asynchronous channel (SCH), and must search for the cell.

The above-mentioned operation, in which the terminal is synchronizedwith the Node-B and an ID of a cell including the terminal is acquired,is called a cell search process. Generally, the cell search isclassified into an initial cell search and a neighbor cell search. Theinitial cell search process is executed when the terminal is initiallypowered on. The neighbor cell search is executed when a connection-modeor idle-mode terminal searches for a neighbor Node-B.

The SCH (Synchronous Channel) may have a hierarchical structure. Forexample, the SCH may use a primary SCH (P-SCH) and a secondary SCH(S-SCH).

The P-SCH and the S-SCH may be contained in a radio frame by a varietyof methods.

FIGS. 3 and 4 show a variety of methods capable of involving the P-SCHand S-SCH in the radio frame. Under a variety of situations, the LTEsystem may configure the SCH according to the structure of FIG. 3 or 4.

In FIG. 3, the P-SCH is contained in the last OFDM symbol of a firstsub-frame, and the S-SCH is contained in the last OFDM symbol of asecond sub-frame (in FIG. 3, duration of a sub-frame is supposed to have0.5 ms. But the length of the sub-frame can be differently configuredaccording to the system).

In FIG. 4, the P-SCH is contained in the last OFDM symbol of a firstsub-frame, and the S-SCH is contained in a second OFDM symbol from thelast OFDM symbol of the first sub-frame (in FIG. 4, also, duration of asub-frame is supposed to have 0.5 ms).

The LTE system can acquire the time/frequency synchronization over theP-SCH. Also, the S-SCH may include a cell group ID, frame synchronousinformation, and antenna configuration information, etc.

The P-SCH configuration method proposed by the conventional 3GPP LTEsystem will hereinafter be described.

The P-SCH is transmitted over the band of 1.08 MHz on the basis of acarrier frequency, and corresponds to 72 sub-carriers. In this case, theinterval among the individual sub-carriers is 15 kHz, because the LTEsystem defines 12 sub-carriers as a single resource block (RB). In thiscase, the 72 sub-carriers are equal to 6 RBs.

The P-SCH is widely used in a communication system (e.g., an OFDM orSC-FDMA system) capable of employing several orthogonal sub-carriers, sothat it must satisfy the following first to fifth conditions.

According to the first condition, in order to allow a reception end todetect a superior performance, the above-mentioned P-SCH must havesuperior auto-correlation and cross-correlation characteristics in atime domain associated with constituent sequences of the P-SCH.

According to the second condition, the above-mentioned P-SCH must allowa low complexity associated with the synchronization detection.

According to the third condition, it is “preferable” that theabove-mentioned P-SCH may have the Nx repetition structure to implementa superior frequency offset estimation performance.

According to the fourth condition, the P-SCH having a low PAPR(Peak-to-Average Power Ratio) or a low CM is preferable.

According to the fifth condition, provided that the P-SCH is used as achannel estimation channel, the frequency response of the P-SCH may havea constant value. In other words, from the viewpoint of the channelestimation, it is well known in the art that a flat response in afrequency domain has the best channel estimation performance.

Although a variety of sequences have been proposed by the conventionalart, the conventional art cannot sufficiently satisfy theabove-mentioned conditions.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a sequence generationmethod for efficient detection, and a method for transmitting/receivingsignals using the same that substantially obviate one or more problemsdue to limitations and disadvantages of the related art.

An object of the present invention is to provide a method for providinga sequence having superior correlation characteristics.

Another object of the present invention is to provide a method forgenerating a sequence in a transmission end, and transmitting thesequence, so that a reception end can easily detect the sequence.

Yet another object of the present invention is to provide a method foreffectively detecting the above-mentioned generated/transmitted signal.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, asignal transmission method comprising: selecting one of root indexescontained in root-index set which enable a first sequence and a secondsequence from among multiple sequences having each of the root indexesin the root-index set to satisfy a conjugate symmetry property;generating a sequence in a frequency domain or a time domain accordingto the selected root index; mapping the generated sequence to afrequency-domain resource element; and converting thefrequency-domain-mapped sequence into a time-domain transmission signal,and transmitting the time-domain transmission signal.

Preferably, the multiple sequences are indicative of Zadoff-Chusequences, and the root-index set satisfying the conjugate symmetryproperty allows the sum of root indexes of each of the first and secondsequences to correspond to a length of the Zadoff-Chu sequences.

Preferably, the Zadoff-Chu sequences have an odd number length, and anequation for generating the Zadoff-Chu sequences is denoted by thefollowing equation:

$\exp \left( {{- i}\; \frac{M\; \pi \; {n\left( {n + 1} \right)}}{N}} \right)$

wherein the length of the Zadoff-Chu sequences is “N”, “M” is a rootindex of the Zadoff-Chu sequence, and “n” is index of each constituentcomponents of one specific Zadoff-Chu sequence.

Preferably, the root-index set, in which the sum of individual rootindexes of the first and second sequences corresponds to the length ofZadoff-Chu sequences, is set to make the sum of the individual rootindexes of the first and second sequences to be set to the value “N”.

Preferably, the length of the Zadoff-Chu sequence is 63, and the rootindex of the first sequence is set to 34, and the root index of thesecond sequence is set to 29.

Preferably, the number of the multiple sequences is three, and the rootindex of a third sequence from among the multiple sequences in theroot-index set is selected in consideration of an influence of afrequency offset.

Preferably, in the root-index set, the root index of the first sequenceis set to 34, the root index of the second sequence is set to 29, andthe root index of the third sequence is set to 25.

Preferably, the multiple sequences are used as P-SCH (Primary-SCH)transmission sequences.

Preferably, the multiple sequences are used as uplink preambletransmission sequences.

In another aspect of the present invention, there is provided a signaltransmission method comprising: selecting one of root indexes containedin root-index set which enable the sum of individual root indexes of afirst sequence and a second sequence from among multiple sequenceshaving each of root indexes in the root-index set to correspond to alength of the multiple sequences; generating the sequence in a frequencydomain or a time domain according to the selected root index; mappingthe generated sequence to a frequency-domain resource element; andconverting the frequency-domain-mapped sequence into a time-domaintransmission signal, and transmitting the time-domain transmissionsignal.

Preferably, the multiple sequences are indicative of Zadoff-Chusequences having an odd number length, and an equation for generatingthe Zadoff-Chu sequences is denoted by the following equation:

$\exp \left( {{- i}\; \frac{M\; \pi \; {n\left( {n + 1} \right)}}{N}} \right)$

wherein the length of the Zadoff-Chu sequences is “N”, the root-indexset, in which the sum of individual root indexes of the first and secondsequences corresponds to the length of multiple sequences, is set tomake the sum of the individual root indexes of the first and secondsequences to be set to the value “N”, where “M” is a root index of theZadoff-Chu sequence, and “n” is index of each constituent components ofone specific Zadoff-Chu sequence.

In yet another aspect of the present invention, there is provided amethod for calculating a cross-correlation value between a received (Rx)signal and each of multiple sequences comprising a first sequence and asecond sequence, the method comprising: achieving a plurality ofintermediate values generated when a cross-correlation value between theRx signal and a first sequence from among the multiple sequences iscalculated; and calculating each of the cross-correlation values betweenthe Rx signal and the first sequence from among the multiple sequencesand between the Rx signal and a second sequence from among the multiplesequences by addition or subtraction of the intermediate values, whereina root index for the first sequence and a root index for the secondsequence are set so that the first sequence and the second sequencesatisfy a conjugate symmetry property.

Preferably, the first sequence and the second sequence, which satisfythe conjugate symmetry property, satisfy a conjugate-complexrelationship from each other.

Preferably, the intermediate values include: a first result valueindicating a cross-correlation value between a real part of the Rxsignal and an real part of the first sequence; a second result valueindicating a cross-correlation value between an imaginary part of the Rxsignal and an imaginary part of the first sequence; a third result valueindicating a cross-correlation value between an imaginary part of the Rxsignal and a real part of the first sequence; and a fourth result valueindicating a cross-correlation value between a real part of the Rxsignal and an imaginary part of the first sequence.

Preferably, the cross-correlation value between the Rx signal and thefirst sequence is calculated so that the sum of the first result valueand the second result value to be a real part, and the deference betweenthe third result value and the fourth result value to be an imaginarypart.

Preferably, the cross-correlation value between the Rx signal and thesecond sequence is calculated so that the difference between the firstresult value and the second result value to be a real part, and the sumof the third result value and the fourth result value to be an imaginarypart.

In yet another aspect of the present invention, there is provided asignal transmission method using a Constant Amplitude ZeroAuto-Correlation (CAZAC) sequence comprising: selecting a predeterminedroot index, and generating the CAZAC sequence in a frequency domain or atime domain according to the selected root index; continuously mappingthe generated CAZAC sequence to a frequency resource element; andconverting the frequency-domain-mapped sequence into a time-domaintransmission signal, and transmitting the time-domain transmissionsignal, wherein the time-domain transmission signal is transmitted in acondition that a specific component corresponding to a part of afrequency “0” from the CAZAC sequence is omitted, so that the resultanttime-domain transmission signal has no component corresponding to thefrequency “0”.

Preferably, the time-domain transmission signal is transmitted afterpuncturing of the component corresponding to the part of the frequency“0” from the CAZAC sequence.

Preferably, the CAZAC sequence is a Zadoff-Chu sequence with an oddnumber length, an equation for generating the Zadoff-Chu sequence isdenoted by the following equation:

$\exp \left( {{- i}\; \frac{M\; \pi \; {n\left( {n + 1} \right)}}{N}} \right)$

wherein the length of the Zadoff-Chu sequence is “N”, “M” is a rootindex of the Zadoff-Chu sequence, and “n” is index of each constituentcomponents of one specific Zadoff-Chu sequence.

Preferably, the length of the Zadoff-Chu sequence is 63, and, in theZadoff-Chu sequence, constituent components corresponding to the “n”value of “0˜30” (i.e., n=0˜30) are continuously mapped to frequencyresource elements from a frequency resource element with a frequencyresource element index of “−31” to a frequency resource element with afrequency resource element index of “−1”, and constituent componentscorresponding to the “n” value of “32˜62” (i.e., n=32˜62) arecontinuously mapped to frequency resource elements from a frequencyresource element with a frequency resource element index of “1” to afrequency resource element with a frequency resource element index of“31”.

Preferably, the Zadoff-Chu sequence is used as a P-SCH (Primary-SCH)transmission sequence.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, illustrate embodiments of the inventionand together with the description serve to explain the principle of theinvention.

In the drawings:

FIG. 1 is a structural diagram illustrating a downlink sub-frame of theIEEE 802.16 system;

FIG. 2 shows the set of sub-carriers transmitted from the 0-th sector ofthe IEEE 802.16 system;

FIGS. 3 and 4 are conceptual diagrams illustrating a variety of methodsincluding the P-SCH and the S-SCH in a radio frame;

FIG. 5 is a block diagram illustrating transmission/reception ends forimplementing one embodiment of the present invention;

FIG. 6 is a flow chart illustrating a method for maintaining rationalcorrelation characteristics and a method for designing a low-PAPRsequence according to the present invention;

FIG. 7 shows auto-correlation characteristics of a CAZAC sequenceaccording to the present invention;

FIG. 8 is a conceptual diagram illustrating a method for constructingthe P-SCH according to the present invention;

FIG. 9 is a flow chart illustrating a method for generating the P-SCHaccording to the present invention;

FIG. 10 is a conceptual diagram illustrating exemplary sub-carriers,each of which is mapped to the P-SCH based on the LTE standard,according to the present invention;

FIG. 11 is a block diagram illustrating a frank sequence with the lengthof 36 in a time domain according to the present invention;

FIG. 12 is a block diagram illustrating the 2× repetition structure in atime domain so that the resultant sequence with the length of 72 isformed according to the present invention;

FIG. 13 shows the result of the step S1703 of FIG. 9 according to thepresent invention;

FIG. 14 shows the result of the step S1704-1 of FIG. 9 according to thepresent invention;

FIG. 15 shows the result of the circular shift to the right of theresult of FIG. 13 according to the present invention;

FIG. 16 is a conceptual diagram illustrating a sequence generationmethod according to the present invention;

FIG. 17 shows the comparison in constellation map between a sequencehaving no DC component and the other sequence having the DC componentaccording to the present invention;

FIG. 18 is a conceptual diagram illustrating a method for designing asequence in a frequency domain so that the 2× repetition structure in atime domain is formed according to the present invention;

FIGS. 19 and 20 are graphs illustrating cross-correlationcharacteristics of the set of (1, 2, 34) indexes according to thepresent invention;

FIG. 21 is a graph illustrating a frequency-offset sensitivity and a CMunder a variety of conditions according to the present invention;

FIGS. 22˜25 are graphs illustrating auto-correlation profiles of theindividual sets when a root-index set is selected according to thepresent invention;

FIG. 26 is a conceptual diagram illustrating a method for mapping thesequence with the length of 63 to a frequency-domain resource elementaccording to the present invention; and

FIGS. 27 and 28 are block diagrams illustrating reception ends accordingto the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

For the convenience of description and better understanding of thepresent invention, the following detailed description will disclose avariety of embodiments and modifications of the present invention. Insome cases, in order to prevent ambiguous concepts of the presentinvention from occurring, conventional devices or apparatuses well knownto those skilled in the art will be omitted and denoted in the form of ablock diagram on the basis of the important functions of the presentinvention.

It should be noted that the present invention generates and transmits asequence so that a reception end can effectively receive or detect acorresponding sequence. For this purpose, the present invention providesa variety of methods for generating/transmitting a sequence for use in aspecific channel, for example, a method for generating a sequence in atime or frequency domain, a method for mapping a sequence generated inthe time or frequency domain to a frequency-domain sequence, a methodfor converting a frequency-domain sequence into a time-domain sequence,a data processing method for removing or avoiding to have a DCcomponent, and a method for generating a sequence having iterative- orrepetitive-characteristics in a time domain, etc.

Basic Embodiment

The sequence generated by the present invention may be applied to avariety of channels.

For example, the sequence may be applied to an uplink preambletransmission signal (e.g., a random access channel (RACH)) or a downlinksynchronization channel, etc. And, the sequence may be applied to a datachannel or a channel for a control signal, and may also be applied tothe synchronization channel which enables time or frequencysynchronization process.

For the convenience of description, although the present invention willdescribe a method for generating a sequence for synchronization channels(e.g., the P-SCH channel), it should be noted that the scope of thepresent invention is not limited to only the following examples, and canalso be applied to other examples.

For example, in the case of transmitting specific information over acorresponding channel without establishing time synchronization,instantaneous correlation output data of the above-mentioned timesynchronization concept is used to acquire corresponding information.Provided that zero-delayed correlation output function is executed, theaforementioned specific information follows the same procedure.

FIG. 5 is a block diagram illustrating transmission/reception ends forimplementing one embodiment of the present invention.

The transmission end will hereinafter be described with reference toFIG. 5. Upon receiving input data 501, the transmission end performs achannel coding 502 for adding redundant bits (also called redundancybits) to the input data 501, so that it can prevent the input data 501from being distorted in a channel.

The channel coding unit 502 may be conducted by a turbo-code or LDPCcode, etc. The channel coding unit 502 may be omitted from a process fortransmitting a synchronization channel or uplink preamble. So, thechannel coding unit 502 is not necessary component to the embodiment ofthis invention providing sequence generation method for used insynchronization channel or method for transmitting uplink preamble.

Thereafter, the resultant data enters symbol mapping unit 504 which canbe implemented with QPSK or 16QAM, etc. Then, the symbol-mapped signalsare loaded on time-domain carriers via the IFFT 505, and the outputsignals of the IFFT 505 are transmitted to a radio-frequency (RF)channel via the filter 506 and the DAC (Digital-to-Analog Converter)507. Operations of the reception end are performed in reverse order ofthose of the transmission end.

FIG. 5 is not one example structure of the transmission end to implementthe sequence generation/transmission method which will be describedbelow.

FIG. 6 is a flow chart for illustrating basic concept ofgenerating/transmitting sequence according to one embodiment of thepresent invention.

Referring to FIG. 6, the sequence generation method generates a sequencewith the length of N in a time or frequency domain at step S101. In thestep S101, one embodiment of this invention propose to select root indexin the root index set which enable at least two sequence having theindexes in that index set meet “the conjugate symmetry property”. Byusing the sequence having the index satisfying the conjugate symmetryproperty, the reception end can easily detect the received signal by onecorrelation operation. The conjugate symmetry property and othercharacteristics of this embodiment will be described later.

On the other hand, if the sequence is generated in the time domain, thesequence generation method performs the N-point FFT operation, so thatthe sequence is mapped to a frequency-domain resource element. But, itshould be noted that the present invention does not limit to a sequencegeneration in time domain, and can be implemented for generatingsequence in frequency domain. So, for the embodiment for generatingsequence in frequency domain, the FFT or DFT step can be omitted.

Meanwhile, according to the requirements of a communication system, thesequence generation method may perform handling DC (Direct Current)component and inserting guard sub-carriers at step S105. In the stepS105, handling DC component is for preventing the generated sequencefrom having DC component in the frequency domain. It can be done bydirectly puncturing the DC component from the sequence, or any otherequivalent operation.

If required, the PAPR attenuation technique may be applied to theresultant sequence at step S107, and a corresponding sequence isconverted into a time-domain sequence by the IDFT or IFT (InverseFourier Transform) operation at step S109. As described above, it isobvious to those skilled in the art that the DFT or FFT may beselectively executed according to the N value.

The sequence generated and/or transmitted by the above scheme can be anuplink preamble, downlink synchronization channel signal, or any otherequivalent signal.

The sequence generation method and the signal transmission methodaccording to the present invention will hereinafter be described in moredetail.

If the sequence with the length of N is generated at step S101, thesequence may select a specific index among index sets having multipleindexes for discriminating among sequences, so that it may be generatedby the selected index.

In this case, as stated above, one embodiment of the present inventionprovides a method for generating sequence by selecting indexes in theindex set, in which at least two of the indexes satisfy the conjugatesymmetry property. In this case, the conjugate symmetry propertyindicates that a sequence corresponding to a specific index is equal toa conjugate complex of another sequence corresponding to anothersequence, and a detailed description thereof will hereinafter bedescribed with reference to the following detailed sequence.

In the case of using at least one sequence among multiple sequences,each of which includes an index satisfying the conjugate symmetryproperty, the reception end can considerably red ce the number ofcalculations of cross-correlations, so that it can easily detect adesired signal.

The present invention provides a method for omitting a componentcorresponding to DC sub-carriers, as shown in S105, and transmitting theresultant signal.

Individual steps of FIG. 6 will hereinafter be described in detail.

Firstly, the step S101 for forming/generating the sequence with thelength of N will hereinafter be described.

According to one embodiment of the present invention, the presentinvention provides not only a method for making the sequence to expresssuperior correlation characteristics but also a method for generating asequence capable of maintaining a predetermined amplitude. For thispurpose, this embodiment generates a sequence with a specific length ina time or frequency domain.

Preferred conditions required for the sequence used for this embodimentwill hereinafter be described.

As described above, in order to increase the efficiency of an amplifierof the transmission end, it is preferable for the transmission end totransmit the sequence for reducing the PAPR. The sequence according tothis embodiment may have a predetermined-amplitude value in the timedomain. It is preferable that the signal amplitude of the sequence maybe slightly changed in not only the time domain but also the frequencydomain.

When most communication methods have allocated a predetermined frequencyband to a specific transmission/reception end, the communication methodshave limited a maximum value of the power capable of being used at theallocated frequency band. In other words, a general communication methodincludes a specific spectrum mask. Therefore, if the signal amplitude isirregular in the frequency domain although the constant-amplitudesequence is transmitted in the time domain, the signal may unexpectedlyexceed the spectrum mask after the sequence has been boosted in thefrequency domain.

If the channel value is pre-recognized under the frequency domain, it ispreferable that the system may perform the power allocation in differentways according to the good or bad status of the channel. However, sincethe system has difficulty in pre-recognizing the channel due tocharacteristics of the preamble usage, the power of the used sub-carrieris generally constant.

In association with the above-mentioned frequency-flat characteristics,in the case of using a corresponding sequence as a specific channel toperform the channel estimation (e.g., if the P-SCH is used in the LTEsystem), there is decided the optimum case in which a reference signalfor the channel estimation may have the frequency-flat characteristics.

Besides the above-mentioned PAPR characteristics, the sequence accordingto this embodiment may have superior correlation characteristics toeasily detect or discriminate signals. The superior cross-correlationcharacteristics indicate the presence of superior auto-correlationcharacteristics and the presence of superior cross-correlationcharacteristics.

It is preferable that the sequence may be generated by the transmissionend so that the reception end can easily acquire the synchronization.The above-mentioned synchronization may indicate the frequencysynchronization and the time synchronization. Generally, if a specificpattern is repeated within a single OFDM symbol in the time domain, thereception end can easily acquire the frequency synchronization and thetime synchronization.

Therefore, the sequence according to this embodiment may be establishedso that a specific pattern is repeated within a single OFDM symbol inthe time domain, but it is not essential. Hereinafter, the non-limitingexample for generating sequence having repeated structure will bedescribed. For example, during the sequence generation step, the systemcan insert a preamble sequence equipped with two identical patternswithin a single OFDM symbol generated by the N-point FFT module. Thereis no limitation in a method for constructing a sequence of a specificlength by repeating the same pattern in the time domain. The followingexamples can be made available.

If the N-point FFT or DFT encounters the serious problem, the sequenceof the length N/2 is created and repeated two times, then, a preamblesequence with the total length N can be configured. If the sequence withthe length N/4 is generated and repeated two times, and the repeatedsequence is inserted, a preamble sequence with the total length N/2 canbe configured. The N/2 preamble sequence may have the length of N/2 inthe frequency domain. In this case, the sequence interval is adjusted inthe frequency domain, so that the sequence with the length of N may begenerated.

In the meantime, as stated above, the present invention may also use anon-repetitive sequence in the time domain. In this case, theabove-mentioned repetitive operation may be omitted as necessary. Inother words, the present invention may also generate the N-lengthsequence in the time domain or directly in frequency domain withoutrepetition of the N-length sequence. The sequence for use in this stepmay be the CAZAC sequence, the Golay sequence, or the binary sequence,etc.

According to this embodiment, there are a variety of sequences capableof being selected in consideration of the above-mentioned conditions. Asan exemplary embodiment, the present invention proposes employing theCAZAC sequence. In more detail, although a method for forming thesequence with the length of 1024 in the time domain of the CAZACsequence, and inserting the same sequence will hereinafter be described,it should be noted that the length of the CAZAC sequence may not belimited to this exemplary method.

According to the CAZAC sequence generated by this embodiment, theroot-index set for discriminating among available CAZAC sequences ispre-generated, and a specific root-index from among the generatedroot-index sets is selected and the sequence according to the selectedindex is generated. In this case, it is preferable that the root-indexselected for the sequence generation may be selected among theroot-index set satisfying the conjugate symmetry property.

In order to satisfy the above-mentioned conjugate symmetry property inthe CAZAC sequence, the sum of two root-indexes from among the index setcan have different conditions according to specific informationindicating whether the sequence length is denoted by an even or oddnumber length. If the corresponding sequence length is denoted by theodd length, and the sum of two root indexes corresponds to a period ofan equation generating the corresponding sequence (in some case, thesequence length), the above-mentioned conjugate symmetry property can besatisfied.

However, the above-mentioned equation for generating the correspondingsequence may be changed from a basic-formatted equation to anotherequation to implement a specific purpose. In this case, the conditionfor satisfying the above-mentioned conjugate symmetry property may bechanged to another condition. Indeed, the sum of both root-indexes mustcorrespond to the period of an equation capable of generally generatinga corresponding sequence. In association with this requirement, adetailed description of the sequence generation method according to thepresent invention will hereinafter be described along with otherembodiments applied to a specific sequence.

The sequence according to the present invention may be generated in thetime and/or frequency domain(s) according to the same principle. For theconvenience of description, the following embodiment will be disclosedon the basis of a specific example which generates the sequence in atime domain and converts the generated sequence into a frequency-domainsequence, because the example which generates the sequence directly in afrequency domain can be easily understood because it is only omittingsome steps of the embodiment for generating sequence in time domain.However, it should be noted that the scope of the present invention maynot be limited to this example, and can also be applied to otherexamples as necessary.

The following description will disclose a specific example shown in thefollowing equation 3.

$\begin{matrix}{{{a_{n} = {\exp \left( {{- j}\; \frac{M\; \pi \; n^{2}}{N}} \right)}},{{when}\mspace{14mu} N\mspace{14mu} {is}\mspace{14mu} {even}}}{{a_{n} = {\exp \left( {{- j}\; \frac{M\; \pi \; {n\left( {n + 1} \right)}}{N}} \right)}},{{when}\mspace{14mu} N\mspace{14mu} {is}\mspace{14mu} {odd}}}} & \left\lbrack {{Equation}\mspace{14mu} 3} \right\rbrack\end{matrix}$

In this example shown in Equation 3, “M” is set to “1” (where “M” is anatural number which is relatively prime to “N”), and a CAZAC (ConstantAmplitude Zero Auto Correlation) sequence with the length of 1024 isgenerated and inserted. This CAZAC sequence has been disclosed in“Polyphase Codes with Good Periodic Correlation Properties” ofInformation Theory IEEE Transaction on, Vol. 18, Issue 4, pp. 531˜532,on July 1972, proposed by David C. Chu.

In Equation 3, “n” is 0, 1, 2, . . . , N−1. Therefore, “N” correspondsto the sequence length or “equivalent sequence length”. The reason why Ncan be denoted as equivalent sequence length is that, as stated above,the generated sequence can have different length from N in specificcase. For example, the sequence may be generated by any alternativeequation for preventing the sequence to have the DC component. Avoidingthe sequence to have the DC component can be implemented by performingdirectly puncturing the DC component in the frequency domain, but,alternatively, the sequence can be generated by omitting one “n” valuewhich corresponds to the DC component. In this case, the resultantsequence length can be “N−1”, not “N”. But, this is a special case, andnormally “N” corresponds to the sequence length. And even in thatspecial case, “N” corresponds to the substantial sequence length orsequence generation period.

Meanwhile, if the sequence length is pre-determined, the presentinvention may use any one of two equations shown in Equation 3 accordingto specific information indicating whether the corresponding sequencehas an even number length or an odd number length.

As described above, a specific pattern available for this embodiment canbe repeated, so that the CAZAC sequence may repeat the specific patternby adjusting the N value. In other words, in Equation 3, under thecondition that the “M” value is set to “1” and the “N” value is set to“512”, the CAZAC sequence is generated and repeated two times, so thatthe sequence with the length of 1024 may be generated.

FIG. 7 shows auto-correlation characteristics of the CAZAC sequenceaccording to the present invention.

As described above, the sequence according to this embodiment may havesuperior correlation characteristics. It can be recognized that theauto-correlation characteristics of the time domain in association withthe CAZAC sequence may have ideal auto-correlation characteristics, asshown in the FIG. 7. In conclusion, it can be recognized that theabove-mentioned CAZAC sequence is an exemplary one of sequencessatisfying various conditions required for this embodiment.

As an optional Step according to this embodiment, the step of mappingthe time domain generated sequence to the frequency domain willhereinafter be described in detail.

According to a method for converting the time-domain sequence into thefrequency-domains sequence according to a predetermined standard of theOFDM system, the N-point FFT process may be executed on the N-lengthsequence generated in the time domain as represented by the followingequation 4, so that the N-length sequence can be converted into afrequency-domain sequence.

$\begin{matrix}{A_{k} = {\sum\limits_{n = 0}^{N - 1}{a_{n}e^{{- j}\; 2\pi \; {{kn}/N}}}}} & \left\lbrack {{Equation}\mspace{14mu} 4} \right\rbrack\end{matrix}$

In Equation 4, “k” is 0, 1, 2, . . . , N−1.

As described above, the time-domain sequence generated in the timedomain can be converted into the frequency-domain sequence “A_(k)”, asrepresented by the Equation 4. Also, for the embodiment for generatingsequence in frequency domain, the frequency domain generated sequenceneed to be mapped to the frequency resource element by equivalentoperation.

In the case of using the CAZAC sequence in this embodiment, it ispreferable that the present invention may continuously map the generatedsequence to a frequency-domain resource element, so that the system canmaintain the CAZAC-sequence property which maintainspredetermined-amplitude characteristics in the time domain (or in thefrequency domain) when the sequence is mapped into the frequency domainresource.

In some embodiments of the present invention, the 2×-repetition sequencein the time domain is used, so that the resultant sequence is mapped tothe frequency domain. In this case, each sequence component in thefrequency domain is mapped to every two sub-carriers. It is assumed thatthe term “Continuous Mapping” in the present invention indicates thatthe sequence is mapped to a specific-number-th sub-carrier containedcontinuously in the frequency domain, and it includes mapping thesequence to every two sub-carriers continuously.

Step S105 for handling the DC sub-carrier and inserting the guardsub-carrier according to one embodiment of the present invention willhereinafter be described with reference to FIG. 6.

Generally, a specific OFDM communication method may request the handlingof the DC sub-carrier and the insertion of a constant guard sub-carrier.If the DC sub-carrier and the guard sub-carrier must be inserted tosatisfy the predetermined standard of the specific OFDM communicationmethod, the above step S105 may be executed.

The above-mentioned handling DC frequency sub-carrier indicates thatdata “0” is inserted into the sub-carrier which has the frequency “0” inthe frequency domain to solve the DC offset problem encountered in theRF unit of the transmission/reception unit. This operation is equivalentto puncturing the DC component.

Not only the above-mentioned method for inserting the data “0” into thesub-carrier having the frequency “0”, but also other methods capable ofacquiring the same effect can be used as necessary.

For example, the component to be mapped to the DC sub-carrier may beomitted in the sequence generation step S101, so that the resultantsequence having no mapping component may be generated. Thereafter,during the step S109 for converting the resultant sequence into thetime-domain sequence, the sequence component corresponding to the DCsub-carrier may be omitted.

Therefore, provided that the component corresponding to the DC componenthaving the frequency “0” in the frequency domain is removed from thesignal transmitted to the time domain, and the sequence having no DCcomponent is transmitted to a destination, a variety of methods can bemade available.

Also, the guard sub-carrier insertion indicates that the guardsub-carriers may be inserted to reduce an Adjacent Channel Interference(ACI).

According to the present invention, when a corresponding signal ismapped to the sub-carrier of the frequency domain, the locations ofsub-carriers of the corresponding signal may be arranged in reverseorder as necessary. For example, the signal is circular-shifted as longas a distance of at least one sub-carrier, and then its mapping processis conducted.

The present invention may also include the random mapping process,however, it is preferable that the location in the frequency domain maynot be changed to another location. The embodiment of the presentinvention will disclose that a specific case in which thefrequency-domain location of the generated signal is not changed toanother location.

Next, as an optional step, step S107 for applying the PAPR attenuationtechnique to the resultant sequence generated by the aforementionedsteps according to the present invention will hereinafter be describedin detail.

As described above, the time-domain signal is modified into anothersignal by the handling the DC and inserting the guard sub-carriers, sothat the PAPR may increase.

This embodiment may perform again the PAPR attenuation technique toreduce the increased PAPR, however, this process is not always necessaryfor the present invention. In this way, during the PAPR attenuationtechnique, it is preferable that the embodiment may minimize thevariation in amplitude level of the frequency-domain sequence codes, andat the same time may apply the PAPR attenuation technique to thefrequency-domain sequence codes.

The resultant frequency-domain sequences are specific valuespre-recognized by the transmission/reception end, so that they can alsobe used as reference signals for other usages (e.g., channelestimation).

According to the embodiment shown in FIG. 6, the step S109 forconverting the above-mentioned sequence into the time-domain sequence bythe IFFT operation will hereinafter be described.

The above step S109 is used to generate the final time-domain preamblesequence, and is conducted as represented by the following equation 5.In this case, the generated sequence may be used to perform thesynchronization, detect signals, or discriminate among the signals.

$\begin{matrix}{a_{n} = {\frac{1}{N}{\sum\limits_{n = 0}^{N - 1}{A_{k}e^{j\; 2\pi \; {{kn}/N}}}}}} & \left\lbrack {{Equation}\mspace{14mu} 5} \right\rbrack\end{matrix}$

It is preferable that a DC component is omitted from the frequencydomain of the resultant signal converted into the time-domain signal atstep S109. By doing so, time/frequency duality of CAZAC sequence can bemaintained.

The above-mentioned embodiment has disclosed the above-mentioned methodfor generating the sequence in the time domain and converting thetime-domain sequence into the frequency-domain sequence, however, itshould be noted that the scope of the inventive sequence is not limitedto only the above-mentioned sequence of the time-domain, and can also beapplied to other examples. In other words, it is well known to thoseskilled in the art that the CAZAC sequence generated in the frequencydomain (e.g., Zadoff-Chu sequence) may be directly mapped to thefrequency-domain resource element.

Embodiment Based on Frank Sequence

A method for applying any one of the above-mentioned CAZAC sequences tothe P-SCH of the 3GPP LTE system (hereinafter referred to as “LTE”according to the present invention will hereinafter be described.

In more detail, after repeating the frank sequence from among the CAZACsequences in the time domain, this embodiment of the present inventionmay generate the P-SCH by processing data in the frequency domain, and adetailed description thereof will hereinafter be described.

The frank sequence is a representative example of the above-mentionedCAZAC sequences, and includes a constant amplitude (i.e., a constantenvelop) in the time and frequency domains. The frank sequence has idealauto-correlation characteristics, and a representative frank sequencehas been disclosed in “Phase Shift Pulse Codes with Good PeriodicCorrelation Properties”, IRE Trans. Inform. Theory, Vol. IT-8, pp.381˜382, on 1962, proposed by R. L. Frank and S. A. Zadoff.

In the meantime, if the P-SCH and the S-SCH are multiplexed according tothe FDM scheme in the LTE system, a method for constructing the P-SCHusing the frank sequence has been previously discussed by associateddevelopers.

However, the inventive method proposed by the present inventionmultiplexes the P-SCH and the S-SCH according to the TDM scheme, and sothat it implements an improved P-SCH superior to the conventional P-SCH.

Next, the comparison between the conventional P-SCH construction methodand the inventive P-SCH construction method will hereinafter bedescribed in detail.

The frank sequence can be represented by the following equation 6:

$\begin{matrix}{\mspace{79mu} {{{a_{k} = {e\text{?}}},\left( {{k = 0},1,\ldots \mspace{14mu},{N - 1}} \right)}{\text{?}\text{indicates text missing or illegible when filed}}}} & \left\lbrack {{Equation}\mspace{14mu} 6} \right\rbrack\end{matrix}$

In Equation 6, I_(k) is shown in the following equation 7:

$\begin{matrix}{I_{k} = {\left\lbrack \frac{k}{m} \right\rbrack \cdot \left( {{k\; {mod}\; m} + 1} \right)}} & \left\lbrack {{Equation}\mspace{14mu} 7} \right\rbrack\end{matrix}$

In Equations 6 and 7, “N” is indicative of the length of the franksequence and must satisfy the condition of N=m². And, “r” is a naturalnumber, which is relative prime to “m” and is less than the value of“m”.

For example, if N=4, the sequences shown in Equation 6 have theconstellation map such as the QPSK. If N=16, the above-mentionedsequences shown in Equation 6 have the constellation map such as theQPSK. If N16 and r=1, the generation of the frank sequence in the timedomain is shown in the following Table 2, and the sequences convertedinto the frequency domain data are shown in the following Table 3:

TABLE 2 In phase Quadrature 0 0 1 1 −1 0 2 0 −1 3 1 0 4 −1 0 5 1 0 6 −10 7 1 0 8 0 −1 9 −1 0 10 0 1 11 1 0 12 1 0 13 1 0 14 1 0 15 1 0

TABLE 3 In phase Quadrature 0 1 0 1 0 1 2 −sqrt(½)  sqrt(½) 3 −sqrt(½) sqrt(½) 4 0 1 5 0 1 6  sqrt(½)  sqrt(½) 7  sqrt(½) −sqrt(½) 8 −1  0 9 01 10  sqrt(½) −sqrt(½) 11 −sqrt(½)  sqrt(½) 12 0 −1  13 0 1 14 −sqrt(½)−sqrt(½) 15  sqrt(½) −sqrt(½)

The result shown in Table 2 is equal to the QPSK modulation result, andthe result of Table 3 has a constant amplitude.

For example, in the case of using the result of Table 3 on the conditionthat the number of actually-used sub-carriers is 16, the system is ableto use the 16 sub-carriers, irrespective of the use or disuse of ascalable bandwidth.

When the timing acquisition is conducted according to thecross-correlation method in the time domain, if objective data ismodulated into another data by the BPSK or M-PSK scheme, the complexityof calculating a correlation value becomes lowered. In this case, theBPSK or M-PSK scheme implements the phase rotation on the constellationmap to involve desired information. In other words, the presentinvention calculates the correlation value based on a simple complexaddition using a simple sign converter, instead of the complexoperation, so that the complexity of calculation becomes lowered.

And, the frank sequence is indicative of the CAZAC sequence, so that ithas superior correlation characteristics in all of the time andfrequency domains.

The frank sequence has a constant value in all of the time and frequencydomains, so that it has a low PAPR. If the frank sequence is used toperform channel estimation, the optimum condition is provided.

For example, if the signal vector “r” received from the time domainunder N=16 and r=1 is represented by r=[r(0) r(1) . . . r(15)], theequation for calculating the correlation value between the signal vector“r” (r=[r(0) r(1) . . . r(15)]) and the well-known signal “a” (a=[a(0)a(1) . . . a(15)]^(H)) and the signal vector can be represented by thefollowing equation 8:

R(d)=r·a  [Equation 8]

In Equation 8, “a” is shown in the above Table 2.

If the R(d) value is directly calculated by the Equation 8, a total of15 complex multiplications and a total of 15 complex additions arerequired to calculate a single value “R(d)”.

However, due to unique properties of the frank sequence “a”, the presentinvention may change a code of a real or imaginary part of a Rx signalto be multiplied to another code, and may perform the addition using thechanged code to calculate the correlation value. Therefore, the presentinvention may finish the above-mentioned calculation using only the 15complex additions other than the complex multiplication.

Typically, the complexity of a single complex multiplication operationis higher than that of the single complex addition operation by about 8times.

The pre-proposed method configures the P-SCH using advantages of thefrank sequence. In other words, there is proposed the FDM-based P-SCHmapped to 64 sub-carriers using the frank sequence with the length of16.

FIG. 8 is a conceptual diagram illustrating a method for constructingthe P-SCH according to the present invention.

Referring to FIG. 8, the frank sequence with the length 16 is insertedinto the frequency domain at intervals of 2 frequency indexes. In otherwords, the sequence of Table 3 is inserted in the frequency domain atintervals of two frequency indexes. In this case, the interval of twofrequency indexes indicates that the m-th sequence is inserted into thek-th sub-carrier, no sequence is inserted into the (k+1)-th sub-carrier,and the (m+1)-th sequence is inserted into the (k+2)-th sub-carrier.

If the above-mentioned sequence inserted into the frequency domain atintervals of two frequency indexes is copied in the frequency domain andis then extended, the other sequence of FIG. 8 mapped to a total of 64sub-carriers can be acquired. The sequence of FIG. 8 is inserted intothe time domain at intervals of two samples, and is then repeated twotimes.

The present invention can improve the above-mentioned P-SCH constructionmethod in the following aspects.

Firstly, the sequence based on the pre-proposed P-SCH constructionmethod includes a specific value having the value “0” in the timedomain, so that the PAPR characteristics are greatly deteriorated. Thepresent invention can improve the deterioration of the PAPRcharacteristics.

The pre-proposed method inserts the sequence into the odd-thsub-carrier, instead of the even-th sub-carrier, to solve the problemcaused by the DC carrier (i.e., the 0-th carrier). Namely, thepre-proposed method inserts data into the sub-carrier having the oddfrequency-index.

In the case of observing the resultant sequence generated by theabove-mentioned scheme in the time domain, the QPSK format under thetime domain (i.e., the frank-sequence advantage) is unavoidably changedto another format, resulting in the occurrence of a fatal problem.Namely, the complexity of the complex operation increases, resulting ininconvenience of use. The present invention aims to solve theabove-mentioned problem.

FIG. 9 is a flow chart illustrating a method for generating the P-SCHaccording to the present invention.

Steps S1701-S1705 of FIG. 9 will hereinafter be described with referenceto other annexed drawings.

FIG. 10 is a conceptual diagram illustrating exemplary sub-carriers,each of which is mapped to the P-SCH based on the LTE standard.

The P-SCH based on the LTE standard is mapped to 73 sub-carriers(including the DC carrier) on the basis of the DC carrier.

This embodiment provides the 2×-repetition sequence structure in thetime domain (i.e., the sequence is repeated two times in the timedomain), so that it can generate 73 sub-carriers (including the DCcarrier) requested by the LTE standard. Namely, the present inventionprovides the sequence having the 2×-repetition structure in the timedomain.

After the DC sub-carriers have been processed, the system uses the franksequence with the length of 71 (not shown in FIG. 10) from among thefrank sequence with the length of 72).

In this case, it is preferable that the 2×-repetition sequence in thetime domain may be set to the frank sequence. Preferably, the length ofthe frank sequence is set to 36, and the variable “r” of Equation 6 isset to “1”. If the length of the frank sequence is set to 36, this franksequence may have the constellation map such as the 6-PSK.

The reason why the length of the frank sequence is set to 36 is toconstruct an objective sequence to be mapped to the 73 sub-carriers. Inother words, if the sequence is generated by two repetitions of the36-length sequence, the resultant sequence can satisfy the LTE standard.

Needless to say, if the repetition format is not desired, the presentinvention may select another sequence with the length of 64 inassociation with the LTE system. If the P-SCH is generated by fourrepetitions of the sequence, the frank sequence with the length of 16may also be used.

Step S1701 of FIG. 9 will hereinafter be described in detail.

Referring to FIG. 9, the frank sequence with the length of N_(pre)=36 isgenerated. In this case, “N_(pre)” is indicative of the length of aninitial sequence generating the P-SCH. In this case, it is preferablethat the variable “r” in Equation 6 is set to “1”.

FIG. 11 is a block diagram illustrating a frank sequence with the lengthof 36 in a time domain according to the present invention.

The sequence of FIG. 11 can be represented by a(i), i=0, 1, . . . , 35.The following Table 4 shows real-part values and imaginary-part valuesof the above value “a(i)”.

TABLE 4 Real Imaginary 0 1 0 1 −cos(pi/3) −sin(pi/3)  2 −1  0 3−cos(pi/3) sin(pi/3) 4  cos(pi/3) sin(pi/3) 5 1 0 6  cos(pi/3)−sin(pi/3)  7 −cos(pi/3) sin(pi/3) 8 1 0

Next, Step S1702 will hereinafter be described in detail.

In the case of using the frank sequence with the length of 36, thissequence is repeated two times in the time domain, so that the resultantsequence is generated.

FIG. 12 is a block diagram illustrating the 2×-repetition sequence inthe time domain so that the resultant sequence with the length of 72 isformed according to the present invention.

Some parts of the 2×-repetition signals of FIG. 12 are shown in thefollowing table 5:

TABLE 5 Real Imaginary 0 1 0 1 −cos(pi/3) −sin(pi/3)  2 −1  0 3−cos(pi/3) sin(pi/3) 4  cos(pi/3) sin(pi/3) 5 1 0 6  cos(pi/3)−sin(pi/3)  7 −cos(pi/3) sin(pi/3) 8 1 0

The sequence values shown in Table 5 are indicative of time-domainvalues.

Next, Step S1703 will hereinafter be described in detail.

The frank sequence with the length of 72 (i.e., the 2×-repetitionsequence in the time domain) generated at step S1702 is converted into afrequency-domain signal by the 72-point FFT or DFT conversion. In thiscase, from the viewpoint of the frequency domain, the 2× repetition isconducted in the time domain, so that it is considered that thealternated insertion from the even-th frequency index in the frequencydomain has been conducted. Namely, the sequence is inserted into theeven-th frequency index as shown in FIG. 13. FIG. 13 shows the result ofthe above step S1703 of FIG. 9.

Some parts of the sequence inserted into the even-th frequency index canbe represented by the following Table 6:

TABLE 6 Real Imaginary 0 Sqrt(2)*1 0 1 0 0 2 Sqrt(2)*cos(pi/9)Sqrt(2)*sin(pi/9)  3 0 0 4  Sqrt(2)*cos(3*pi/9) Sqrt(2)*sin(3*pi/9) 5 00 6  −Sqrt(2)*cos(3*pi/9)  Sqrt(2)* sin(3*pi/9) 7 0 0 8 −Sqrt(2)*cos(pi/9)  −Sqrt(2)* sin(pi/9)   9 0 0

Next, Step S1704 will hereinafter be described in detail.

This step S1704 is adapted to solve the problem caused by the DCsub-carriers. If the DC sub-carrier part of the communication standardto be used is not used (e.g., if the value of 0 is to be transmittedover the DC sub-carrier), it is preferable that the step S1704 may beperformed.

The present invention provides two methods for solving theabove-mentioned DC sub-carrier problem. For the convenience ofdescription and better understanding of the present invention, the stepS1704-1 will be firstly described in detail, and the step S1704-2 willbe then described in detail.

The step S1704-1 is adapted to perform puncturing of a correspondingsequence located at the DC sub-carrier. In other words, the term“Puncturing” indicates that the corresponding sequence isnullification-processed with the value of “0”.

FIG. 14 shows the result of the step S1704-1.

If the step S1704-1 is conducted on the result of FIG. 13, the result ofFIG. 14 can be acquired.

Some parts of the result of FIG. 14 can be represented by the followingTable 7:

TABLE 7 Real Imaginary 0 0 0 1 0 0 2 Sqrt(2)*cos(pi/9) Sqrt(2)*sin(pi/9)  3 0 0 4  Sqrt(2)*cos(3*pi/9) Sqrt(2)*sin(3*pi/9) 5 00 6 −Sqrt(2)*cos(3*pi/9)  Sqrt(2)* sin(3*pi/9) 7 0 0 8 −Sqrt(2)*cos(pi/9)  −Sqrt(2)* sin(pi/9)  

Next, Step S1704-2 will hereinafter be described.

The step S1704-2 is adapted to perform mapping of the correspondingsequence except for the DC sub-carrier.

The 2×-repetition sequence is made at the above step S1702. Therefore,the result of the step S1703 is configured in the form of a specificsequence, which is inserted into the frequency domain at intervals oftwo frequency indexes. In other words, it should be noted that thesequence is inserted into the even-th frequency index.

In this case, the present invention performs the step S1704-2, so thatthe generated sequence is CS (Circular Shift)—processed to the right orleft side.

FIG. 15 shows the CS-result to the right side of the result of FIG. 13according to the present invention. Some parts of the result of FIG. 15can be represented by the following Table 8:

TABLE 8 Real Imaginary 0 0 0 1 Sqrt(2)*1 0 2 0 0 3 Sqrt(2)*cos(pi/9) Sqrt(2)*sin(pi/9)   4 0 0 5  Sqrt(2)*cos(3*pi/9) Sqrt(2)*sin(3*pi/9)  60 0 7 −Sqrt(2)*cos(3*pi/9) Sqrt(2)* sin(3*pi/9) 8 0 0

If the above step S1704-1 is compared with the other step S1704-2, itcan be recognized that the step S1704-1 is more preferable than the stepS1704-2.

The step S1704-1 may easily calculate the correlation value using theknown signals of Table 5. A detailed method for calculating thecorrelation value will hereinafter be described.

Since the sequence is inserted into the odd-th index at step S1704-2,the time-domain sequence value is changed to another, so that thepresent invention has difficulty in calculating the correlation valueusing the simple calculation due to the changed sequence value.

Needless to say, the reception end moves the carrier frequency from acurrent location to another location by the sub-carrier spacing betweensub-carriers, and may receive the resultant signal. However, the firstsub-carrier is used as the DC component, so that it may unavoidablyencounter the DC offset. As a result, the step S1704-1 is superior tothe step S1704-2 in the light of the DC offset problem. Needless to say,the multiplication of a specific complex number is performed in the timedomain after the above-mentioned reception action, and the frequencyshift may then be conducted. However, if the multiplication of thespecific complex number is adapted to calculate the simple correlationvalue, the efficiency may be excessively deteriorated.

Next, Step S1705 will hereinafter be described. The step S1705 is usedas an additional step for a specific case in which the reception enddoes not perform the down sampling and is applied to the 128-point FFTprocess.

The above step S1705 may be effectively used when the reception end doesnot support the down-sampling function.

For example, the sub-carrier spacing between the sub-carriers of the LTEsystem is 15 kHz. If the 128-point FFT (or the 128-point DFT) is appliedto the LTE system, 128 sample values occur in the time domain, and the128 sample values may have the sampling frequency of 1.92 MHz. Thereception end filters the Rx signal (i.e., the received signal) at thefrequency of 1.08 MHz, and may select any one of the followingoperations (i.e., first and second operations).

According to the first operation, the reception end uses the samplingfrequency of 1.92 MHz without any change. According to the secondoperation, the reception end performs the down-sampling using thesampling frequency of 1.08 MHz, and uses the down-sampling result.

The step S1705 is used as an additional step for a specific case inwhich the reception end does not perform the down-sampling process andemploys the sampling frequency of 1.92 MHz without any change.

If the up-sampling process is required, the step S1705 performs theup-sampling of the sequence generated at the frequency 1.08 MHz(corresponding to 72 samples), so that the sequence with the frequency1.08 MHz is up-sampling-processed to another frequency of 1.92 MHz. Thedigital sampling method basically inserts the value of “0” into 56sub-carriers (56=128−72), and performs the 128-point IFFT process on theabove zero-padding result.

A detailed sampling technique has been well known to those skilled inthe art, so that a detailed description thereof will be omitted. Forreference, the sequence of Table 7 or 8 should be used in acorresponding band (i.e., the band of 1.08 MHz) during the transmissionprocess.

Operations of the reception end having received the P-SCH sequence willhereinafter be described in detail. The cross-correlation method for usein the reception end will hereinafter be described.

The above-mentioned example shows the 2×-repetition structure in thetime domain. So, a predetermined range of the Rx signal is decidedaccording to the auto-correlation scheme, and then the cross-correlationscheme is applied to the decided range, so that the fine synchronizationacquisition process can be conducted.

The method for determining a predetermined range of the Rx signalrepeated by the auto-correlation scheme is identical with theconventional method for use in the conventional art. So, a method forreducing the number of calculations according to the cross-correlationscheme will hereinafter be described.

The timing acquisition method based on the cross-correlation scheme canbe represented by the following equation 9:

$\begin{matrix}\left. {\left. {\left. \mspace{79mu} {{\hat{d} = {\arg\limits_{d}\max \left\{ {R(d)} \middle| {0 \leq d \leq {N_{f} - 1}} \right\}}}{{R(d)} = {\left( {\sum\limits_{m = o}^{M - 1}{{\sum\limits_{n = {m\; L}}^{{{({m + 1})}L} - 1}{{p^{*}(n)}{r\left( {d + n} \right)}}}}^{2}} \right)/{\sum\limits_{n = 0}^{{N_{fft}/2} - 1}{{r\left( {d + n} \right)}}^{2}}}}} \right) + {\left( {\sum\limits_{m = 0}^{M - 1}{{\sum\limits_{n = {m\; L}}^{{{({m + 1})}L} - 1}{{p^{*}\left( {\frac{N_{fft}}{2} + n} \right)}{r\left( {\frac{N_{fft}}{2} + d + n} \right)}}}}^{2}} \right)/{\sum\limits_{n = 0}^{{N_{fft}/2} - 1}{{r\left( {\frac{N_{fft}}{2} + d + n} \right)}}^{2}}}} \right)\mspace{20mu} {\left( {N_{fft}/2} \right) = {ML}}} \right) & \left\lbrack {{Equation}\mspace{14mu} 9} \right\rbrack\end{matrix}$

In Equation 9, p(n) is indicative of the known P-SCH sequence value inthe time domain, r(n) is indicative of the Rx signal, M is indicative ofthe “M” value for the partial correlation method, N_(fft) is the FFTmagnitude, and {circumflex over (d)} is indicative of the detectedtiming acquisition location.

If the P-SCH has no repetition format, and a maximum value of thefrequency offset at the frequency band of 2 GHz is 5 ppm, the system mayhave the sufficient performances under M=1 of Equation 9. Therefore,there is no need for the present invention to apply the partialcorrelation method to the repeated interval.

Based on Equation 9, the LTE system performs the down-sampling (i.e., 72samples) of the Rx signal using the sampling frequency of 1.08 MHz, andthe P-SCH has two symbols within the term of 10 ms.

So, if the time synchronization is acquired by the averaging of the 5 msterm, the calculation complexity for the timing acquisition can berepresented by the following equation 10:

(72 complex multiplications+72 complex additions+2 complexpower-calculations)*9600  [Equation 10]

In order to explain the method for calculating the correlation valueaccording to the present invention, the frank sequence shown in Table 4will be described as an example.

If the Rx signal is denoted by r=[r(0) r(1) r(2), . . . , r(35)], themethod for calculating the Rx signal and the correlation value of Table4 can be conducted by the following parallel process.

Firstly, the real value can be conducted as represented by the followingequation 11, and the imaginary value can be conducted as represented bythe following equation 12:

$\begin{matrix}{\mspace{79mu} {{{Real}\mspace{14mu} {value}\text{:}}{{{Real}\left\lbrack {r(0)} \right\rbrack} - {{Real}\left\lbrack {r(2)} \right\rbrack} + {{Real}\left\lbrack {r(5)} \right\rbrack} + {{Real}\left\lbrack {r(8)} \right\rbrack} + {{Real}\left\lbrack {r(11)} \right\rbrack} + {{Real}\left\lbrack {r(13)} \right\rbrack} - {{Real}\left\lbrack {r(14)} \right\rbrack} + {{Real}\left\lbrack {r(15)} \right\rbrack} - {{Real}\left\lbrack {r(16)} \right\rbrack} + {{Real}\left\lbrack {r(17)} \right\rbrack} - {{Real}\left\lbrack {r(18)} \right\rbrack} + {{Real}\left\lbrack {r(20)} \right\rbrack} + {{Real}\left\lbrack {r(23)} \right\rbrack} - {{Real}\left\lbrack {r(26)} \right\rbrack} + {{Real}\left\lbrack {r(29)} \right\rbrack} + {{Real}\left\lbrack {r(31)} \right\rbrack} + {{Real}\left\lbrack {r(32)} \right\rbrack} + {{Real}\left\lbrack {r(33)} \right\rbrack} + {{Real}\left\lbrack {r(34)} \right\rbrack} + {{Real}\left\lbrack {r(35)} \right\rbrack} + {{\cos \left( {{pi}/3} \right)}^{*}\left\{ {{- {{Real}\left\lbrack {r(1)} \right\rbrack}} - {{Real}\left\lbrack {r(3)} \right\rbrack} + {{Real}\left\lbrack {r(4)} \right\rbrack} + {{Real}\left\lbrack {r(6)} \right\rbrack} - {{Real}\left\lbrack {r(7)} \right\rbrack} - {{Real}\left\lbrack {r(9)} \right\rbrack} - {{Real}\left\lbrack {r(10)} \right\rbrack} - {{Real}\left\lbrack {r(12)} \right\rbrack} - {{Real}\left\lbrack {r(19)} \right\rbrack} - {{Real}\left\lbrack {r(21)} \right\rbrack} - {{Real}\left\lbrack {r(22)} \right\rbrack} - {{Real}\left\lbrack {r(24)} \right\rbrack} - {{Real}\left\lbrack {r(25)} \right\rbrack} - {{Real}\left\lbrack {r(27)} \right\rbrack} + {{Real}\left\lbrack {r(28)} \right\rbrack} + {{Real}\left\lbrack {r(30)} \right\rbrack}} \right\}} + {{\sin \left( {{pi}/3} \right)}^{*}\left\{ {{- {{Imag}\left\lbrack {r(1)} \right\rbrack}} + {{Imag}\left\lbrack {r(3)} \right\rbrack} + {{Imag}\left\lbrack {r(4)} \right\rbrack} - {{Imag}\left\lbrack {r(6)} \right\rbrack} + {{Imag}\left\lbrack {r(7)} \right\rbrack} - {{Imag}\left\lbrack {r(9)} \right\rbrack} + {{Imag}\left\lbrack {r(10)} \right\rbrack} - {{Imag}\left\lbrack {r(12)} \right\rbrack} - {{Imag}\left\lbrack {r(19)} \right\rbrack} + {{Imag}\left\lbrack {r(21)} \right\rbrack} - {{Imag}\left\lbrack {r(22)} \right\rbrack} + {{Imag}\left\lbrack {r(24)} \right\rbrack} + {{Imag}\left\lbrack {r(25)} \right\rbrack} - {{Imag}\left\lbrack {r(27)} \right\rbrack} - {{Imag}\left\lbrack {r(28)} \right\rbrack} + {{Imag}\left\lbrack {r(30)} \right\rbrack}} \right\}}}}} & \left\lbrack {{Equation}\mspace{14mu} 11} \right\rbrack \\{\mspace{79mu} {{{Imaginary}\mspace{14mu} {value}\text{:}}{{{Imag}\left\lbrack {r(0)} \right\rbrack} - {{Imag}\left\lbrack {r(2)} \right\rbrack} + {{Imag}\left\lbrack {r(5)} \right\rbrack} + {{Imag}\left\lbrack {r(8)} \right\rbrack} + {{Imag}\left\lbrack {r(11)} \right\rbrack} + {{Imag}\left\lbrack {r(13)} \right\rbrack} - {{Imag}\left\lbrack {r(14)} \right\rbrack} + {{Imag}\left\lbrack {r(15)} \right\rbrack} - {{Imag}\left\lbrack {r(16)} \right\rbrack} + {{Imag}\left\lbrack {r(17)} \right\rbrack} - {{Imag}\left\lbrack {r(18)} \right\rbrack} + {{Imag}\left\lbrack {r(20)} \right\rbrack} + {{Imag}\left\lbrack {r(23)} \right\rbrack} - {{Imag}\left\lbrack {r(26)} \right\rbrack} + {{Imag}\left\lbrack {r(29)} \right\rbrack} + {{Imag}\left\lbrack {r(31)} \right\rbrack} + {{Imag}\left\lbrack {r(32)} \right\rbrack} + {{Imag}\left\lbrack {r(33)} \right\rbrack} + {{Imag}\left\lbrack {r(34)} \right\rbrack} + {{Imag}\left\lbrack {r(35)} \right\rbrack} + {{\cos \left( {{pi}/3} \right)}^{*}\left\{ {{- {{Imag}\left\lbrack {r(1)} \right\rbrack}} - {{Imag}\left\lbrack {r(3)} \right\rbrack} + {{Imag}\left\lbrack {r(4)} \right\rbrack} + \left. \quad{{{Imag}\left\lbrack {r(6)} \right\rbrack} - {{Imag}\left\lbrack {r(7)} \right\rbrack} - {{Imag}\left\lbrack {r(9)} \right\rbrack} - {{Imag}\left\lbrack {r(10)} \right\rbrack} - {{Imag}\left\lbrack {r(12)} \right\rbrack} - {{Imag}\left\lbrack {r(19)} \right\rbrack} - {{Imag}\left\lbrack {r(21)} \right\rbrack} - {{Imag}\left\lbrack {r(22)} \right\rbrack} - {{Imag}\left\lbrack {r(24)} \right\rbrack} - {{Imag}\left\lbrack {r(25)} \right\rbrack} - {{Imag}\left\lbrack {r(27)} \right\rbrack} + {{Imag}\left\lbrack {r(28)} \right\rbrack} + {{Imag}\left\lbrack {r(30)} \right\rbrack}} \right\} - {{\sin \left( {{pi}/3} \right)}^{*}\left\{ {{- {{Real}\left\lbrack {r(1)} \right\rbrack}} + {{Real}\left\lbrack {r(3)} \right\rbrack} + {{Real}\left\lbrack {r(4)} \right\rbrack} - {{Real}\left\lbrack {r(6)} \right\rbrack} + {{Real}\left\lbrack {r(7)} \right\rbrack} - {{Real}\left\lbrack {r(9)} \right\rbrack} + {{Real}\left\lbrack {r(10)} \right\rbrack} - {{Real}\left\lbrack {r(12)} \right\rbrack} - {{Real}\left\lbrack {r(19)} \right\rbrack} + {{Real}\left\lbrack {r(21)} \right\rbrack} - {{Real}\left\lbrack {r(22)} \right\rbrack} + {{Real}\left\lbrack {r(24)} \right\rbrack} + {{Real}\left\lbrack {r(25)} \right\rbrack} - {{Real}\left\lbrack {r(27)} \right\rbrack} - {{Real}\left\lbrack {r(28)} \right\rbrack} + {{Real}\left\lbrack {r(30)} \right\rbrack}} \right\}}} \right.}}}} & \left\lbrack {{Equation}\mspace{14mu} 12} \right\rbrack\end{matrix}$

In the case of expressing the complexity of Equations 11 and 12, thefollowing equation 13 can be acquired:

((52*2) real additions+(2*2) real multiplications)*9600=(104 realadditions+4 real multiplications)*9600  [Equation 13]

In the case of comparing the Equation 13 with the Equation 10, there isa large difference in complexity between the Equation 13 and theEquation 10.

Also, since the value “cos(pi/3)” is “½” (i.e., cos(pi/3)=½), this value“cos(pi/3)=½” corresponds to the 1-bit shift of the hardwareimplementation, so that this value can be negligible in light of thenumber of calculations. In this case, the number of calculations can berepresented by the following equation 14:

((51*2) real additions+(1*2) real multiplications)*9600=(102 realadditions+2 real multiplications)*9600  [Equation 14]

Also, the value of “sin(pi/3)” is equal to sqrt(3)/2 or 0.8660 (i.e.,sin(pi/3)=sqrt(3)/2=0.8660), so that the number of calculationsapproximates 0.75(=½+¼). In this case, the approximated result can beimplemented with the bit shift. So, if the number of calculations isignored, the complexity becomes lowered as represented by the followingequation 15:

((51*2) real additions+(1*2) real additions)*9600=(102 realadditions)*9600  [Equation 15]

In the meantime, the positive mark (+) or the negative mark (−) can beeasily implemented by the code inverter, so that these marks are notcontained in the number of calculations.

The above-mentioned example is repeated two times in the time domain, sothat the P-SCH is configured. However, the detailed numerals have beendisclosed for only illustrative purposes of the present invention, sothat the scope of the present invention is not limited to theabove-mentioned detailed numerals and can also be applied to otherexamples.

For example, the initial sequence may be set to the frank sequence withthe length of 16. In other words, the frank sequence with the length of16 is generated at step S1701. The frank sequence with the length of 16is repeated four times in the time domain at step S1702. The franksequence is converted into the frequency-domain sequence by the 64 FFTat step S1703. In this case, the sequence is inserted in the frequencydomain at intervals of four frequency indexes.

At step 1704, the present invention may perform the puncturing processat the DC-carrier location, or may perform the sequence insertionsimultaneously while avoiding the DC carrier. Thereafter, the sequenceis converted into the time-domain signal, and the step S1705 may beexecuted as necessary.

In the case of using the above-mentioned basic embodiments of thepresent invention and applying the embodiments to the frank sequence, itis preferable that all the generated sequences may be generated usingthe selected index under the condition the above-mentioned conjugatesymmetry property is satisfied.

In the case of selecting the sequence by selecting an index from amongthe index set satisfying the conjugate symmetry property, the number ofcalculations can be greatly reduced in the reception end which detectsthe signal using the cross-correlation.

The following description relates to a specific case in which acommunication system based on the above-mentioned correlation techniquegenerates/uses the sequence as described above.

Aspect for Use in Communication System Based on Correlation Technique

For the convenience of description, the following description will bebased on the frequency-synchronization sequence or thetime-synchronization sequence (e.g., the Primary Synchronization Code(PSC) for the P-SCH), the sequences proposed by individual embodimentsof the present invention may be applied to an uplink preambletransmission channel (e.g., RACH), any other downlink synchronouschannel, a signaling, a control channel, and ACK/NACK communicationfields.

Typically, a correlation metric component of the calculation procedurefor acquiring the time synchronization includes a delay component, asrepresented by (R(d)).

However, if the time synchronization is not acquired, the correlationmetric caused by the delay component is not required.

If the concept of the present invention is applied to a time-synchronouschannel, the delay component (d) must be considered. Otherwise, if theconcept of the present invention is applied to other channel irrelevantto the time synchronization, there is no need to consider the delaycomponent (d).

Next, considering the above-mentioned delay component (d), there areproposed a variety of equations. However, it is obvious to those skilledin the art that the proposed equations can be equally applied to theother case having no delay component (i.e., d=0). So, the case having nodelay component will be omitted for the convenience of description.

Next, a method for generating/using at least one sequence from amongmultiple sequences will hereinafter be described, so that the generatedsequence is used as the frequency- and time-synchronization sequence.Namely, the above-mentioned sequence generation method does not use acommon sequence with a single cell, but selects a specific sequence fromamong multiple predetermined sequences and uses the selected sequence.

The sequence for the frequency and time synchronization within the cellmay be called a primary sequence code (PSC).

For example, if the P-SCH is designed using a single common sequencewithin a single cell, it is determined that the cell common PSC isapplied to this P-SCH. Otherwise, if the P-SCH is designed using one ofmultiple sequences within a single cell, it is determined that aspecific PSC is selected from among multiple PSCs.

The present invention provides a method for generating sequence fromamong multiple available sequences so that the reception end cancalculate correlation values between received signal and each of themultiple sequences using only one correlation operation.

If the P-SCH is designed using the frank sequence of Equation 6, thesequence with the length of 16 and the other sequence with the length of36 may be used. In this case, if the length N is “16”, the variable “m”of Equation 6 is “4”, so that two kinds of frank sequences are used.Also, if the length N is “36”, the variable “m” of Equation 6 is “6”, sothat two kinds of sequences are used. In this case, the presentinvention may not support three or more PSCs, resulting in theoccurrence of a serious problem.

The present invention provides a method for generating thesynchronization-channel sequence available for a variety ofcommunication systems, but this method can support a variety ofsynchronization channels under the single cell.

There is no limitation in types of the above-mentioned variouscommunication systems. For the convenience of description, the presentinvention will be described on the basis of the LTE system.

This embodiment will explain the Zadoff-Chu sequence by referring to thefollowing equation 16, so that it can propose a method for generating aplurality of PSCs. The Zadoff-Chu sequence has already been disclosed inEquation 3.

$\begin{matrix}{{a^{m}(k)} = \left\{ {{{\begin{matrix}{{\exp\left( {- \frac{{jm}\; \pi \; k^{2}}{L}} \right)},{{when}\mspace{14mu} L\mspace{14mu} {is}\mspace{14mu} {even}}} \\{{\exp\left( {- \frac{{jm}\; \pi \; {k\left( {k + 1} \right)}}{L}} \right)},{{when}\mspace{14mu} L\mspace{14mu} {is}\mspace{14mu} {odd}}}\end{matrix}k} = 0},1,\ldots \mspace{14mu},{L - 1}} \right.} & \left\lbrack {{Equation}\mspace{14mu} 16} \right\rbrack\end{matrix}$

In Equation 16, “m” is a natural number of less than “L” and isrelatively prime to “L”. For example, if L=8, “m” is set to 1, 3, 5, and7.

This embodiment provides a method for generating a sequence from among aplurality of available sequences using the Zadoff-Chu sequence.Preferably, the synchronous channel generated by the sequence accordingto the present invention may follow the structure of FIG. 10.

The sequence according to this embodiment may be generated by theprocedure of FIG. 16. FIG. 16 is a conceptual diagram illustrating anexemplary sequence generation method according to the present invention.

Referring to FIG. 16, the sequence generation method effectively selectsa sequence index from among a plurality of sequence indexes (or theindex set) to generate a sequence at step S10. If sequence index isselected, the sequence generation method generates the sequence in thetime or frequency domain according to the selected index at step S20. Inthis case, the sequence may be repeated N times in the time domain atstep S30, but this step can be omitted.

The generated sequence may be mapped to the frequency resource elementat step S40. A data process for removing the DC component from thefrequency domain may be executed at step S51 or S52.

If the data process for removing the DC component is executed, the dataprocess for converting the sequence into the time-domain sequence isconducted at step S60.

According to this embodiment of the present invention, a variety ofmethods other than the above-mentioned methods may also be used toremove the DC component. According to the present invention, under thecondition that a specific component corresponding to the part having thefrequency “0” may be omitted from the frequency domain of acorresponding sequence during the time-domain transmission, the presentinvention may use an arbitrary method for satisfying the above-mentionedcondition.

Next, individual steps will hereinafter be described in detail.

The step S10 for effectively selecting a sequence index from among theplurality of sequence indexes (or the index set) will be described indetail. In the step S10, the sequence index set may comprise the onemother sequence index or the root index, and the remaining sequenceindexes. In more detail, if the reception end aims the timingacquisition, it is preferable that the one root index and the remainingsequence indexed satisfy the condition that the cross-correlation valuecan be calculated with less number of calculations by the reception end.So, this embodiment propose the root index set to have the one rootsequence index and the remaining sequence indexes meet the abovecondition.

Meanwhile, the number of PSCs available in the cell may be determined invarious ways. For example, a specific case in which the P-SCH isconfigured using one of 4 PSCs will hereinafter be described. If 3 PSCsare required only, and 4 PSCs are available, then 3 PSCs from among the4 PSCs may also be used as necessary.

This embodiment may prepare 3 root indexes to employ the 3 PSCs, so thatthe index to be generated from among the prepared root indexes may beselected.

Next, the method for generating the sequence using the Zadoff-Chusequence with the length “36” or “32” will hereinafter be described. Inthis case, a method for generating the P-SCH by repeating the sequencetwo times will hereinafter be described.

The Zadoff-Chu sequence with the length 36 or 32 may be generated byEquation 16.

If the length (L) is 36 as denoted by Equation 16, the value “m”indicating the sequence index is 1, 5, 7, 11, 13, 17, 19, 23, 25, 29,31, 33, and 35. If the length (L) is 32, the value “m” indicating thesequence index is 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29,and 31.

If the length (L) is 36, one of the values 1, 5, 7, 11, 13, 17, 19, 23,25, 29, 31, 33, and 35 is determined to be a mother sequence index. Ifthe length (L) is 32, one of the values 1, 3, 5, 7, 9, 11, 13, 15, 17,19, 21, 23, 25, 27, 29, and 31 is set to the mother sequence index. Forthe convenience of description, the mother sequence index is denoted by“m_(o)”, and the remaining sequence indexes are denoted by “m_(i)”.

In order to satisfy the conjugate symmetry property between the mothersequence index “m_(o)” and the remaining sequence index “m”, it ispreferable that the relationship of Equation 17 may be established.

m _(o) +m _(i)=½×P _(L) ×n

or

m _(o) −m _(i)=±½×P _(L) ×n  [Equation 17]

n=1, 2, 3, . . .

In Equation 17, “P_(L)” is indicative of a value corresponding to asingle period equal to 2*pi in a polyphase sequence. Typically, thevalue of a denominator of the phase component in the sequence generationequation corresponds to the value equal to a single period.

In other words, in the case of the polyphase sequence, theabove-mentioned conjugate symmetry property is relevant to an integermultiple of the half of the sequence generation period in the sequencegeneration equation.

If the “k” value corresponding to the part having the frequency “0” isomitted from several “k” values shown in Equation 16, and then thesequence is generated, the period of the generated sequence is shorterthan a normal period by the value “1”, and the sequence length (L′) isshorter than the sequence length (L) by the value “1”. As a result,during the sequence generation, the part having the frequency “0” isomitted from the frequency domain, and then the sequence is generated.

In order to select the root index maintaining the conjugate symmetryproperty while the above-mentioned process is conducted, the sum ofindexes or the difference between the indexes may correspond to aninteger multiple of L/2 in association with the L value instead of theL′ value. Therefore, provided that the sum of root indexes correspondsto an integer value associated with the half of the period or sequencelength, this means that a sequence generation period or the sequencelength (L) provided when a normal sequence generation equation is used.

In the meantime, the following equations 18 and 19 show the applicationexamples of Equation 17.

m _(o) +m _(i)=½×√{square root over (L)}×n

or

m _(o) −m _(i)=±½×√{square root over (L)}×n  [Equation 18]

n=1, 2, 3, . . .

As shown in Equation 16, the value corresponding to a single period inthe Zadoff-Chu sequence is equal to the sequence length L. Therefore,the generation period of Equation 18 is equal to “L”. If the same methodis applied to the frank sequence, Equation 20 can be acquired. In themeantime, the value corresponding to a single period is set to √{squareroot over (L)}.

As shown in Equation 18, if the mother sequence index (m_(o)) and theremaining sequence index (m_(i)) are decided, the reception end caneasily calculate the cross-correlation value.

For example, if a single value “m_(o)” and three values (m₁, m₂, and m₃)are selected and then the sequence is generated, the reception end mustcalculate the cross-correlation value using four sequences. Namely,after receiving an unknown signal, the reception end calculates each ofthe cross-correlation values among the m_(o), m_(i), m₂, and m₃sequences stored in the reception end, and must determine whether theunknown signal is the m_(o) sequence, the m₁ sequence, the m₂ sequence,or the m₃ sequence using the calculated cross-correlation values.

However, if at least one of the sequences satisfying the conjugatesymmetry property is received, the present invention calculates thecross-correlation amplitude of the selected one of the sequences m₀˜m₃,so that the cross-correlation amplitudes f the remaining sequences aredetermined. The detailed operations of the reception end will bedescribed later with reference to other embodiments.

For example, if the sequence length L is 32, the mother sequence indexmay be set to “1”. In this case, if “1” is substituted into the m₀ valueof a first expression of Equation 18, and “32” is substituted into the“L” value, the m₁ value is equal to “15”. If “1” is substituted into them₀ value of a second expression of Equation 18, and “32” is substitutedinto the “L” value, the m₂ value is equal to “17”. If the m₁ and Lvalues are substituted into the first expression of Equation 18, the m₃value is equal to “31”. In this case, the m₀, m₁, m₂, and m₃ value maybe determined to be a single index group.

In brief, if a single mother sequence index is decided, its associatedindex group may also be decided.

If the length is set to 32, the values m₀=3, m₁=13, m₂=19, and m₃=29 maybe determined to be a single index group. Needless to say, other setscan also be made available. If 8 sequences are used, the presentinvention needs to select only two groups using the same method.

If the sequence length L is 36, the values m₀=1, m₁=17, m₂=19, and m₃=35may be determined to be a single index group. Also, the values m₀=5,m₁=13, m₂=23, and m₃=31 may be determined to be a single index group.

If the L value is denoted by a prime number (i.e., L=37), the valuesm₀=1 and m₁=36 are determined to be a single group or the other valuesm₀=3 and m₁=16 may be determined to be a single group.

If the L value is an odd number, Equation 18 can be simplified asrepresented by the following Equation 19:

m ₀ +m _(i) =L  [Equation 19]

If sequences corresponding to the sequence indexes selected by Equation19 are used, all the correlation operations can be completed by a singlecorrelation operation in the same manner as in Equation 19.

Equation 19 corresponds to the subset of Equations 17 and 18.

The selected sequences according to the present invention may beZadoff-Chu sequences, all the CAZAC sequences, or polyphase sequencescomposed of an exponential function. For example, the selected sequencesmay be frank sequences. However, if the selected sequences aredetermined to be the frank sequences, Equations 18 and 19 are modifiedinto the following equation 21.

The following equations 20 and 21 may also correspond to the subset ofEquation 17.

m _(o) +m _(i)=½×√{square root over (L)}×n

or

m _(o) −m _(i)=±½×L×n  [Equation 20]

n=1, 2, 3, . . .

m _(o) +m _(i)=√{square root over (L)}  [Equation 21]

The sequences selected by this embodiment may be truncated Zadoff-Chusequences as necessary. In the case of generating the Zadoff-Chusequence, the sequence length is set to a prime number, many moresequences can be acquired. In this case, some bits are truncated, sothat the truncated Zadoff-Chu sequence may be configured. For example,if the length L is discarded after the sequence with the length 36 isgenerated, the sequence with the length 36 can be generated.

As can be seen from Equation 19, two sequence index groups processedonce may be generated. For example, if the Zadoff-Chu sequence with thelength 37 is provided, the index group or the index set may be set toeither one of (1-36), (2-35), (3-34), (4-33), (5-32), (6-31), (7-30),(8-29), (9-28), (10-27), (11-26), (12-25), (13-24), (14-23), (15-22),(16-21), (17-20), and (18-19).

Since the equation 19 is a specialized format of Equation 18, thesequence indexes satisfying Equation 19 correspond to the other sequenceindexes satisfying Equation 18.

As described above, all the sequence indexes may be selected accordingto Equation 17, or may also be selected by other methods. For example,some sequence indexes are selected by Equation 17, and either one of theselected sequence indexes is CS (Circular Shift)—processed by apredetermined amplitude, so that a new sequence may be selectedaccording to the CS-processed result.

For example, the sequence indexes “1” and “31”, each of which has thelength 32, are selected. In this case, the sequence corresponding to thesequence index “1” or “31” may be CS-processed by the half of thesequence length, so that a new sequence can be selected according to theCS-processed result. In other words, the sequence with the length 32corresponding to the sequence index “1” or “31” is CS-processed by “16”,so that a new third sequence can be selected according to the16-CS-processed result.

It should be noted that the above-mentioned numerical values have beendisclosed for only illustrative purposes, so that the concept of thepresent invention is not limited to only the above-mentioned numericalvalues, and can also be applied to other examples as necessary.

For the convenience of description, an exemplary case in which thesequence length L is set to 32 or 36 will hereinafter be described.

If the length is set to 32, an exemplary case in which the values m₀=1,m₁=15, m₂=17, and m₃=31 are set to a single index group will bedescribed. If the length is set to 36, an exemplary case in which thevalues m₀=1, m₁=17, m₂=19, and m₃=35 are set to a single index groupwill be described.

Step S20 of FIG. 16 for generating a sequence in a time domain or afrequency domain according to the selected sequence will hereinafter bedescribed.

In the case of using Equation 16, a sequence of a single index groupwhich has the length of 36 and the values m₀=1, m₁=17, m₂=97, and m₃=35can be generated. The following Table 9 shows examples of the generatedsequences.

TABLE 9 m₀ = 1 Real Imag m₁ = 17 Real Imag m₂ = 19 Real Imag m₃ = 35Real Imag 0 1 0 0 1 0 0 1 0 0 1 0 1 0.99619 −0.087156 1 0.087156−0.99619 1 −0.08716 −0.99619 1 −0.99619 −0.087156 2 0.93969 −0.34202 20.93969 0.34202 2 0.93969 −0.34202 2 0.93969 0.34202 3 0.70711 −0.707113 0.70711 −0.70711 3 −0.70711 −0.70711 3 −0.70711 −0.70711 4 0.17365−0.98481 4 0.17365 0.98481 4 0.17365 −0.98481 4 0.17365 0.98481 5−0.57358 −0.81915 5 0.81915 0.57358 5 −0.81915 0.57358 5 0.57358−0.81915 6 −1 0 6 −1 0 6 −1 0 6 −1 0 7 −0.42262 0.90631 7 −0.906310.42262 7 0.90631 0.42262 7 0.42262 0.90631 8 0.76604 0.64279 8 0.76604−0.64279 8 0.76604 0.64279 8 0.76604 −0.64279 9 0.70711 −0.70711 90.70711 −0.70711 9 −0.70711 −0.70711 9 −0.70711 −0.70711 10 −0.76604−0.64279 10 −0.76604 0.64279 10 −0.76604 −0.64279 10 −0.76604 0.64279 11−0.42262 0.90631 11 −0.90631 0.42262 11 0.90631 0.42262 11 0.422620.90631 12 1 0 12 1 0 12 1 0 12 1 0 13 −0.57358 −0.81915 13 0.819150.57358 13 −0.81915 0.57358 13 0.57358 −0.81915 14 −0.17365 0.98481 14−0.17365 −0.98481 14 −0.17365 0.98481 14 −0.17365 −0.98481 15 0.70711−0.70711 15 0.70711 −0.70711 15 −0.70711 −0.70711 15 −0.70711 −0.7071116 −0.93969 0.34202 16 −0.93969 −0.34202 16 −0.93969 0.34202 16 −0.93969−0.34202 17 0.99619 −0.087156 17 0.087156 −0.99619 17 −0.08716 −0.9961917 −0.99619 −0.087156 18 −1 0 18 −1 0 18 −1 0 18 −1 0 19 0.99619−0.087156 19 0.087156 −0.99619 19 −0.08716 −0.99619 19 −0.99619−0.087156 20 −0.93969 0.34202 20 −0.93969 −0.34202 20 −0.93969 0.3420220 −0.93969 −0.34202 21 0.70711 −0.70711 21 0.70711 −0.70711 21 −0.70711−0.70711 21 −0.70711 −0.70711 22 −0.17365 0.98481 22 −0.17365 −0.9848122 −0.17365 0.98481 22 −0.17365 −0.98481 23 −0.57358 −0.81915 23 0.819150.57358 23 −0.81915 0.57358 23 0.57358 −0.81915 24 1 0 24 1 0 24 1 0 241 0 25 −0.42262 0.90631 25 −0.90631 0.42262 25 0.90631 0.42262 250.42262 0.90631 26 −0.76604 −0.64279 26 −0.76604 0.64279 26 −0.76604−0.64279 26 −0.76604 0.64279 27 0.70711 −0.70711 27 0.70711 −0.70711 27−0.70711 −0.70711 27 −0.70711 −0.70711 28 0.76604 0.64279 28 0.76604−0.64279 28 0.76604 0.64279 28 0.76604 −0.64279 29 −0.42262 0.90631 29−0.90631 0.42262 29 0.90631 0.42262 29 0.42262 0.90631 30 −1 0 30 −1 030 −1 0 30 −1 0 31 −0.57358 −0.81915 31 0.81915 0.57358 31 −0.819150.57358 31 0.57358 −0.81915 32 0.17365 −0.98481 32 0.17365 0.98481 320.17365 −0.98481 32 0.17365 0.98481 33 0.70711 −0.70711 33 0.70711−0.70711 33 −0.70711 −0.70711 33 −0.70711 −0.70711 34 0.93969 −0.3420234 0.93969 0.34202 34 0.93969 −0.34202 34 0.93969 0.34202 35 0.99619−0.087156 35 0.087156 −0.99619 35 −0.08716 −0.99619 35 −0.99619−0.087156

The result of Table 9 relates to four sequences. Either one of the foursequences may be configured in the form of FIG. 11. However, FIG. 11relates to the frank sequence, and the result of Table 9 relates to theZadoff-Chu sequence.

In the case of using Equation 16, the sequence result associated with asingle index group which has the length of 32 and the values m₀=1,m₁=15, m₂=17, and m₃=31 can be generated. The following Table 10 showsexamples of the generated sequences.

TABLE 10 m₀ = 1 Real Imag m₁ = 15 Real Imag m₂ = 17 Real Imag m₃ = 31Real Imag 0 1 0 0 1 0 0 1 0 0 1 0 1 0.99518 −0.098017 1 0.098017−0.99518 1 −0.098017 −0.99518 1 −0.99518 −0.098017 2 0.92388 −0.38268 20.92388 0.38268 2 0.92388 −0.38268 2 0.92388 0.38268 3 0.63439 −0.773013 0.77301 −0.63439 3 −0.77301 −0.63439 3 −0.63439 −0.77301 4 0 −1 4 0 14 0 −1 4 0 1 5 −0.77301 −0.63439 5 0.63439 0.77301 5 −0.63439 0.77301 50.77301 −0.63439 6 −0.92388 0.38268 6 −0.92388 −0.38268 6 −0.923880.38268 6 −0.92388 −0.38268 7 0.098017 0.99518 7 −0.99518 −0.098017 70.99518 −0.098017 7 −0.098017 0.99518 8 1 0 8 1 0 8 1 0 8 1 0 9−0.098017 −0.99518 9 0.99518 0.098017 9 −0.99518 0.098017 9 0.098017−0.99518 10 −0.92388 0.38268 10 −0.92388 −0.38268 10 −0.92388 0.38268 10−0.92388 −0.38268 11 0.77301 0.63439 11 −0.63439 0.77301 11 0.63439−0.77301 11 −0.77301 0.63439 12 0 −1 12 0 1 12 0 −1 12 0 1 13 −0.634390.77301 13 −0.77301 0.63439 13 0.77301 0.63439 13 0.63439 0.77301 140.92388 −0.38268 14 0.92388 0.38268 14 0.92388 −0.38268 14 0.923880.38268 15 −0.99518 0.098017 15 −0.098017 0.99518 15 0.098017 0.99518 150.99518 0.098017 16 1 0 16 1 0 16 1 0 16 1 0 17 −0.99518 0.098017 17−0.098017 0.99518 17 0.098017 0.99518 17 0.99518 0.098017 18 0.92388−0.38268 18 0.92388 0.38268 18 0.92388 −0.38268 18 0.92388 0.38268 19−0.63439 0.77301 19 0.77301 0.63439 19 0.77301 0.63439 19 0.634390.77301 20 0 −1 20 0 1 20 0 −1 20 0 1 21 0.77301 0.63439 21 −0.63439−0.77301 21 0.63439 −0.77301 21 −0.77301 0.63439 22 −0.92388 0.38268 22−0.92388 −0.38268 22 −0.92388 0.38268 22 −0.92388 −0.38268 23 −0.098017−0.99518 23 0.99518 0.098017 23 −0.99518 0.098017 23 0.098017 −0.9951824 1 0 24 1 0 24 1 0 24 1 0 25 0.098017 0.99518 25 −0.99518 −0.098017 250.99518 −0.098017 25 −0.098017 0.99518 26 −0.92388 0.38268 26 −0.92388−0.38268 26 −0.92388 0.38268 26 −0.92388 −0.33268 27 −0.77301 −0.6343927 0.63439 0.77301 27 −0.63439 0.77301 27 0.77301 −0.63439 28 0 −1 28 01 28 0 −1 28 0 1 29 0.63439 −0.77301 29 0.77301 −0.63439 29 −0.77301−0.63439 29 −0.63439 −0.77301 30 0.92388 −0.38268 30 0.92388 0.38268 300.92388 −0.38268 30 0.92388 0.38268 31 0.99518 −0.098017 31 0.098017−0.99518 31 0.098017 −0.99518 31 −0.99518 −0.098017

Step S30 for repeating the sequence N times in the time domain in FIG.16 will hereinafter be described.

Step S30 may be omitted for the convenience of description, and the “N”value may be freely determined.

The result of FIG. 9, i.e., the 2×-repetition structure in the timedomain, will hereinafter be described with reference to Tables 11 and12. The following Tables 11 and 12 show the repetition result of Table9.

TABLE 11 m₀ = 1 Real Imag m₁ = 17 Real Imag m₂ = 19 Real Imag m₃ = 35Real Imag 0 1 0 0 1 0 0 1 0 0 1 0 1 0.99619 −0.087156 1 0.087156−0.99619 1 −0.08716 −0.99619 1 −0.99619 −0.087156 2 0.93969 −0.34202 20.93969 0.34202 2 0.93969 −0.34202 2 0.93969 0.34202 3 0.70711 −0.707113 0.70711 −0.70711 3 −0.70711 −0.70711 3 −0.70711 −0.70711 4 0.17365−0.98481 4 0.1736. 0.98481 4 0.17365 −0.98481 4 0.17365 0.98481 5−0.57358 −0.81915 5 0.81915 0.57358 5 −0.81915 0.57353 5 0.57358−0.81915 6 −1 0 6 −1 0 6 −1 0 6 −1 0 7 −0.42262 0.90631 7 −0.906310.42262 7 0.90631 0.42262 7 0.42262 0.90631 8 0.76604 0.64279 8 0.76604−0.64279 8 0.76604 0.64279 8 0.76604 −0.64279 9 0.70711 −0.70711 90.70711 −0.70711 9 −0.70711 −0.70711 9 −0.70711 −0.70711 10 −0.76604−0.64279 10 −0.76604 0.64279 10 −0.76604 −0.64279 10 −0.76604 0.64279 11−0.42262 0.90631 11 −0.90631 0.42262 11 0.90631 0.42262 11 0.422620.90631 12 1 0 12 1 0 12 1 0 12 1 0 13 −0.57353 −0.81915 13 0.819150.57358 13 −0.81915 0.57356 13 0.57356 −0.81915 14 −0.17365 0.98481 14−0.17365 −0.98481 14 −0.17365 0.98481 14 −0.17365 −0.98481 15 0.70711−0.70711 15 0.70711 −0.70711 15 −0.70711 −0.70711 15 −0.70711 −0.7071116 −0.93969 0.34202 16 −0.93969 −0.34202 16 −0.93969 0.34202 16 −0.93969−0.34202 17 0.99619 −0.087156 17 0.087156 −0.99619 17 −0.08716 −0.9961917 −0.99619 −0.087156 18 −1 0 18 −1 0 18 1 0 18 −1 0 19 0.99619−0.087156 19 0.087156 −0.99619 19 −0.08716 −0.99619 19 −0.99619−0.087156 20 −0.93969 0.34202 20 −0.93969 −0.34202 20 −0.93969 0.3420220 −0.93969 −0.34202 21 0.70711 −0.70711 21 0.70711 −0.70711 21 −0.70711−0.70711 21 −0.70711 −0.70711 22 −0.17365 0.98481 22 −0.17365 −0.9848122 −0.17365 0.98481 22 −0.17365 −0.98481 23 −0.57353 −0.81915 23 0.819150.57358 23 −0.81915 0.57358 23 0.57358 −0.81915 24 1 0 24 1 0 24 1 0 241 0 25 −0.42262 0.90631 25 −0.90631 0.42262 25 0.90631 0.42262 250.42262 0.90631 26 −0.76604 −0.64279 26 −0.76604 0.64279 26 −0.76604−0.64279 26 −0.76604 0.64279 27 0.70711 −0.70711 27 0.70711 −0.70711 27−0.70711 −0.70711 27 −0.70711 −0.70711 28 0.76604 0.64279 28 0.76604−0.64279 28 0.76604 0.64279 28 0.76604 −0.64279 29 −0.42262 0.90631 29−0.90631 0.42262 29 0.90631 0.42262 29 0.42262 0.90631 30 1 0 30 −1 0 30−1 0 30 −1 0 31 −0.57358 −0.81915 31 0.81915 0.57358 31 −0.81915 0.5735331 0.57353 −0.81915 32 0.17365 −0.98481 32 0.17365 0.98481 32 0.17365−0.93481 32 0.17365 0.98431 33 0.70711 −0.70711 33 0.70711 −0.70711 33−0.70711 −0.70711 33 −0.70711 −0.70711 34 0.93969 −0.34202 34 0.939690.34202 34 0.93969 −0.34202 34 0.93969 0.34202 35 0.99619 −0.087156 350.087156 −0.99619 35 −0.08716 −0.99619 35 −0.99619 −0.087156

TABLE 12 m₀ = 1 Real Imag m₁ = 17 Real Imag m₂ = 19 Real Imag m₃ = 35Real Imag 36 1 0 36 1 0 36 1 0 36 1 0 37 0.99619 −0.087156 37 0.087156−0.99619 37 −0.08716 −0.99619 37 −0.99619 −0.087156 38 0.93969 −0.3420238 0.93969 0.34202 38 0.93969 −0.34202 38 0.93969 0.34202 39 0.70711−0.70711 39 0.70711 −0.70711 39 −0.70711 −0.70711 39 −0.70711 −0.7071140 0.17365 −0.98481 40 0.17365 0.98481 40 0.17365 −0.93481 40 0.173650.98431 41 −0.57358 −0.81915 41 0.81915 0.57358 41 −0.81915 0.57358 410.57358 −0.31915 42 −1 0 42 −1 0 42 −1 0 42 −1 0 43 −0.42262 0.90631 43−0.90631 0.42262 43 0.90631 0.42262 43 0.42262 0.90631 44 0.766040.64279 44 0.76604 −0.64279 44 0.76604 0.64279 44 0.76604 −0.64279 450.70711 −0.70711 45 0.70711 0.70711 45 −0.70711 −0.70711 45 −0.70711−0.70711 46 −0.76604 −0.64279 46 −0.76604 0.64279 46 −0.76604 −0.6427946 −0.76604 0.64279 47 −0.42262 0.90631 47 −0.90631 0.42262 47 0.906310.42262 47 0.42262 0.90631 48 1 0 48 1 0 48 1 0 48 1 0 49 −0.57358−0.81915 49 0.81915 0.57358 49 −0.81915 0.57358 49 0.57358 −0.81915 50−0.17365 0.98481 50 −0.17365 −0.98481 50 −0.17365 0.98481 50 −0.17365−0.98481 51 0.70711 −0.70711 51 0.70711 −0.70711 51 −0.70711 −0.70711 51−0.70711 −0.70711 52 −0.93969 0.34202 52 −0.93969 −0.34202 52 −0.939690.34202 52 −0.93969 −0.34202 53 0.99619 −0.087156 53 0.087156 −0.9961953 −0.08716 −0.99619 53 −0.99619 −0.087156 54 1 0 54 −1 0 54 1 0 54 −1 055 0.99619 −0.087156 55 0.087156 −0.99619 55 −0.08716 −0.99619 55−0.99619 −0.087156 56 −0.93969 0.34202 56 −0.93969 −0.34202 56 −0.939690.34202 56 −0.93969 −0.34202 57 0.70711 −0.70711 57 0.70711 −0.70711 57−0.70711 −0.70711 57 −0.70711 −0.70711 58 −0.17365 0.98481 58 −0.17365−0.98481 58 −0.17365 0.98481 58 −0.17365 −0.98481 59 −0.57358 −0.8191559 0.81915 0.57358 59 −0.81915 0.57358 59 0.57358 −0.81915 60 1 0 60 1 060 1 0 60 1 0 61 −0.42262 0.90631 61 −0.90631 0.42262 61 0.90631 0.4226261 0.42262 0.90631 62 −0.76604 −0.64279 62 −0.76604 −0.64279 62 −0.76604−0.64279 62 −0.76604 0.64279 63 0.70711 −0.70711 63 0.70711 −0.70711 63−0.70711 −0.70711 63 −0.70711 −0.70711 64 0.76604 0.64279 64 0.76604−0.64279 64 0.76604 0.64279 64 0.76604 −0.64279 65 −0.42262 0.90631 65−0.90631 0.42262 65 0.90631 0.42262 65 0.42262 0.90631 66 −1 0 66 −1 066 −1 0 66 −1 0 67 −0.57358 −0.81915 67 0.81915 0.57358 67 −0.819150.57358 67 0.57358 −0.81915 68 0.17365 −0.98481 68 0.17365 0.98481 680.17365 −0.98481 68 0.17365 0.98481 69 0.70711 −0.70711 69 0.707110.70711 69 −0.70711 −0.70711 69 −0.70711 −0.70711 70 0.93969 −0.34202 700.93969 0.34202 70 0.93969 −0.34202 70 0.93969 0.34202 71 0.99619−0.087156 71 0.087156 −0.99619 71 −0.08716 −0.99619 71 −0.99619−0.087156

An example acquired when the result of Table 10 is repeated two times inthe time domain will hereinafter be described with reference to Tables13 and 14. As can be seen from Tables 13 and 14, the result of Table 10is repeated once more.

TABLE 13 m₀ = 1 Real Imag m₁ = 15 Real Imag m₂ = 17 Real Imag m₃ = 31Real Imag  0   1   0  0   1   0  0   1   0  0   1   0  1   0.99518−0.098017  1   0.098017 −0.99518  1 −0.098017 −0.99518  1 −0.99518−0.098017  2   0.92388 −0.38268  2   0.92388   0.38268  2   0.92388−0.38268  2   0.92388   0.38266  3   0.63439 −0.77301  3   0.77301−0.63439  3 −0.77301 −0.63439  3 −0.63439 −0.77301  4   0 −1  4   0   1 4   0 −1  4   0   1  5 −0.77301 −0.63439  5   0.63439   0.77301  5−0.63439   0.77301  5   0.77301 −0.63439  6 −0.92388   0.38268  6−0.92388 −0.38268  6 −0.92388   0.38268  6 −0.92388 −0.38268  7  0.098017   0.99518  7 −0.99518 −0.098017  7   0.99518 −0.098017  7−0.098017   0.99518  8   1   0  8   1   0  8   1   0  8   1   0  9−0.098017 −0.99518  9   0.99518   0.098017  9 −0.99518   0.098017  9  0.098017 −0.99518 10 −0.92388   0.38268 10 −0.92388 −0.38268 10−0.92388   0.38268 10 −0.92388 −0.38268 11   0.77301   0.63439 11−0.63439 −0.77301 11   0.63439 −0.77301 11 −0.77301   0.63439 12   0 −112   0   1 12   0 −1 12   0   1 13 −0.63439   0.77301 13 −0.77301  0.63439 13   0.77301   0.63439 13   0.63439   0.77301 14   0.92388−0.38268 14   0.92388   0.38268 14   0.92388 −.38268 14   0.92388  0.38268 15 −0.99518   0.098017 15 −0.09807   0.99518 15   0.098017  0.99518 15   0.99518   0.098017 16   1   0 16   1   0 16   1   0 16  1   0 17 −0.99518   0.098017 17 −0.098017   0.99518 17   0.098017  0.99518 17   0.99518   0.098017 18   0.92388 −0.38268 18   0.92388  0.38268 18   0.92388 −0.38268 18   0.92388   0.38268 19 −0.63439  0.77301 19 −0.77301   0.63439 19   0.77301   0.63439 19   0.63439  0.77301 20   0 −1 20   0   1 20   0 −1 20   0   1 21   0.77301  0.63439 21 −0.63439 −0.77301 21   0.63439 −0.77301 21 −0.77301  0.63439 22 −0.92388   0.38268 22 −0.92388 −0.38268 22 −0.92388  0.38268 22 −0.92388 −0.38268 23 −0.098017 −0.99518 23   0.99518  0.098017 23 −0.99518   0.098017 23   0.09807 −0.99518 24   1   0 24  1   0 24   1   0 24   1   0 25   0.098017   0.99518 25 −0.99518−0.098017 25   0.99518 −0.098017 25 −0.098017   0.99518 26 −0.92388  0.38268 26 −0.92388 −0.38268 26 −0.92388   0.38268 26 −0.92388−0.38268 27 −0.77301 −0.63439 27   0.63439   0.77301 27 −0.63439  0.77301 27   0.77301 −0.63439 28   0 −1 28   0   1 28   0 −1 28   0  1 29   0.63439 −0.77301 29   0.77301 −0.63439 29 −0.77301 −0.63439 29−0.63439 −0.77301 30   0.92388 −0.38268 30   0.92388   0.38268 30  0.92388 −0.38268 30   0.92388   0.38268 31   0.99518 −0.098017 31  0.098017 −0.99518 31 −0.098017 −0.99518 31 −0.99518 −0.098017 32   1  0 32   1   0 32   1   0 32   1   0

TABLE 14 m₀ = 1 Real Imag m₁ = 15 Real Imag m₂ = 17 Real Imag m₃ = 31Real Imag 33   0.99518 −0.098017 33   0.098017 −0.99518 33 −0.098017−0.99513 33 −0.99513 −0.098017 34   0.92388 −0.38268 34   0.92388  0.38268 34   0.92388 −0.38263 34   0.92388   0.38268 35   0.63439−0.77301 35   0.77301 −0.63439 35 −0.77301 −0.63439 35 −0.63439 −0.7730136   0 −1 36   0   1 36   0 −1 36   0   1 37 −0.77301 −0.63439 37  0.63439   0.77301 37 −0.63439   0.77301 37   0.77301 −0.63439 38−0.92388   0.38268 38 −0.92388 −0.38268 38 −0.92388   0.38268 38−0.92388 −0.38268 39   0.098017   0.99518 39 −0.99518 −0.098017 39  0.99518 −0.098017 39 −0.098017   0.99518 40   1   0 40   1   0 40   1  0 40   1   0 41 −0.098017 −0.99518 41   0.99518   0.098017 41 −0.99518  0.098017 41   0.098017 −0.99518 42 −0.92388   0.33268 42 −0.92388−0.33268 42 −0.92388   0.38263 42 −0.92388 −0.38268 43   0.77301  0.63439 43 −0.63439 −0.77301 43   0.63439 −0.77301 43 −0.77301  0.63439 44   0   1 44   0   1 44   0 −1 44   0   1 45 −0.63439  0.77301 45 −0.77301   0.63439 45   0.77301   0.63439 45   0.63439  0.77301 46   0.92388 −0.38268 46   0.92388   0.38268 46   0.92388−0.38268 46   0.92388   0.38268 47 −0.99518   0.098017 47 −0.098017  0.99518 47   0.098017   0.99513 47   0.99513   0.098017 48   1   0 48  1   0 48   1   0 48   1   0 49 −0.99518   0.098017 49 −0.098017  0.99518 49   0.098017   0.99518 49   0.99518   0.098017 50   0.92388−0.33268 50   0.92333   0.33268 50   0.92388 −0.38263 50   0.92388  0.38263 51 −0.63439   0.77301 51 −0.77301   0.63439 51   0.77301  0.63439 51   0.63439   0.77301 52   0 −1 52   0   1 52   1   0 52   0  1 53   0.77301   0.63439 53 −0.63439 −0.77301 53   0.63439 −0.77301 53−0.77301   0.63439 54 −0.92388   0.38268 54 −0.92388 −0.38268 54−0.92388   0.38268 54 −0.92388 −0.38268 55 −0.098017 −0.99518 55  0.99518   0.098017 55 −0.99518   0.098017 55   0.098017 −0.99518 56  1   0 56   1   0 56   1   0 56   1   0 57   0.098017   0.99518 57−0.99518 −0.098017 57   0.99518 −0.098017 57 −0.098017   0.99518 58−0.92388   0.33268 58 −0.92383 −0.33268 53 −0.92388   0.38263 58−0.92388 −0.38268 59 −0.77301 −0.63439 59   0.63439   0.77301 59−0.63439   0.77301 59   0.77301 −0.63439 60   0 −1 60   0 −1 60   0 −160   0   1 61   0.63439 −0.77301 61   0.77301 −0.63439 61 −0.77301−0.63439 61 −0.63439 −0.77301 62   0.92388 −0.38268 62   0.92388  0.38268 62   0.92388 −0.38268 62   0.92388   0.38268 63   0.99518−0.098017 63   0.09801 −0.99518 63 −0.093017 −0.99518 63 −0.99518−0.098017

Next, Step S40 for mapping the time-domain sequence to a frequencydomain in FIG. 16 will hereinafter be described. However, it should benoted that the sequence according to the present invention may begenerated from the frequency domain, so that it may be directly mappedto the frequency resource element as necessary.

If the sequence with the 2×-repetition structure is mapped to thefrequency domain, a specific sequence is generated in the frequentdomain. In this case, this specific sequence has a frequency componentat only even-th frequency indexes of the frequency domain due to theDFT-operation characteristics.

In more detail, if the sequences of Tables 11 and 12 are mapped to thefrequency domain, the following sequences shown in Tables 15 and 16 canbe acquired.

If the sequences of Tables 13 and 14 are mapped to the frequency domain,the following sequences shown in Tables 17 and 18 can be acquired.

TABLE 15 m₀ = 1 Real Imag m₁ = 17 Real Imag m₂ = 19 Real Imag m₃ = 35Real Imag 0 1 −1 0 1 −1 0 −1 −1 0 −1 −1 1 0 0 1 0 0 1 0 0 1 0 0 2 1.0834−0.90904 2 1.0834 0.90904 2 1.0834 −0.90904 2 1.0834 0.90904 3 0 0 3 0 03 0 0 3 0 0 4 1.2817 −0.59767 4 0.59767 −1.2817 4 −0.59767 −1.2817 4−1.2817 −0.59767 5 0 0 5 0 0 5 0 0 5 0 0 6 1.4142 0 6 1.4142 0 6 1.41420 6 1.4142 0 7 0 0 7 0 0 7 0 0 7 0 0 8 1.1585 0.81116 8 −0.81116 −1.15858 0.81116 −1.1585 8 −0.1585 0.81116 9 0 0 9 0 0 9 0 0 9 0 0 10 0.245581.3927 10 0.24558 −1.3927 10 0.24558 1.3927 10 0.24558 −1.3927 11 0 0 110 0 11 0 0 11 0 0 12 −1 1 12 −1 1 12 1 1 12 1 1 13 0 0 13 0 0 13 0 0 130 0 14 −1.3289 −0.48369 14 −1.3289 0.48369 14 −1.3289 −0.48369 14−1.3289 0.48369 15 0 0 15 0 0 15 0 0 15 0 0 16 0.12326 −1.4088 16 1.4088−0.12326 16 −1.4088 −0.12326 16 −0.12326 −1.4088 17 0 0 17 0 0 17 0 0 170 0 18 1.4142 0 18 1.4142 0 18 1.4142 0 18 1.4142 0 19 0 0 19 0 0 19 0 019 0 0 20 −0.12326 1.4088 20 −1.4088 0.12326 20 1.4088 0.12326 200.12326 1.4088 21 0 0 21 0 0 21 0 0 21 0 0 22 −1.3289 −0.48369 22−1.3289 0.48369 22 −1.3289 −0.48369 22 −1.3289 0.48369 23 0 0 23 0 0 230 0 23 0 0 24 1 −1 24 1 −1 24 −1 −1 24 −1 −1 25 0 0 25 0 0 25 0 0 25 0 026 0.24558 1.3927 26 0.24558 −1.3927 26 0.24558 1.3927 26 0.24558−1.3927 27 0 0 27 0 0 27 0 0 27 0 0 28 −1.1585 −0.81116 28 0.811161.1585 28 −0.81116 1.1585 28 1.1585 −0.81116 29 0 0 29 0 0 29 0 0 29 0 030 1.4142 0 30 1.4142 0 30 1.4142 0 30 1.4142 0 31 0 0 31 0 0 31 0 0 310 0 32 −1.2817 0.59767 32 −0.59767 1.2717 32 0.59767 1.2817 32 1.28170.59767 33 0 0 33 0 0 33 0 0 33 0 0 34 1.0834 −0.90904 34 1.0834 0.9090434 1.0834 −0.90904 34 1.0834 0.90904 35 0 0 35 0 0 35 0 0 35 0 0

TABLE 16 m₀ = 1 Real Imag m₁ = 17 Real Imag m₂ = 19 Real Imag m₃ = 35Real Imag 36 −1 1 36 −1 1 36 1 1 36 1 1 37 0 0 37 0 0 37 0 0 37 0 0 381.0834 −0.90904 38 1.0834 0.90904 38 1.0834 −0.90904 38 1.0834 0.9090439 0 0 39 0 0 39 0 0 39 0 0 40 −1.2817 0.59767 40 −0.59767 1.2718 400.59767 1.2817 40 1.2817 0.59767 41 0 0 41 0 0 41 0 0 41 0 0 42 1.4142 042 1.4142 0 42 1.4142 0 42 1.4142 0 43 0 0 43 0 0 43 0 0 43 0 0 44−1.1585 −0.81116 44 0.81116 1.1585 44 −0.81116 1.1585 44 1.1585 −0.8111645 0 0 45 0 0 45 0 0 45 0 0 46 0.24558 1.3927 46 0.24558 −1.3927 460.24558 1.3927 46 0.24558 −1.3927 47 0 0 47 0 0 47 0 0 47 0 0 48 1 −1 481 −1 48 −1 −1 48 −1 −1 49 0 0 49 0 0 49 0 0 49 0 0 50 −1.3289 −0.4836950 −1.3289 0.48369 50 −1.3289 −0.48369 50 −1.3289 0.48369 51 0 0 51 0 051 0 0 51 0 0 52 −0.12326 1.4088 52 −1.4088 0.12326 52 1.4088 0.12326 520.12326 1.4088 53 0 0 53 0 0 53 0 0 53 0 0 54 1.4142 0 54 1.4142 0 541.4142 0 54 1.4142 0 55 0 0 55 0 0 55 0 0 55 0 0 56 0.12326 −1.4088 561.4088 −0.12326 56 −1.4088 −0.12326 56 −0.12326 −1.4088 57 0 0 57 0 0 570 0 57 0 0 58 −1.3289 −0.48369 58 −1.3289 0.48369 58 −1.3289 −0.48369 58−1.3289 0.48369 59 0 0 59 0 0 59 0 0 59 0 0 60 −1 1 60 −1 1 60 1 1 60 11 61 0 0 61 0 0 61 0 0 61 0 0 62 0.24558 1.3927 62 0.24558 −1.3927 620.24558 1.3927 62 0.24558 −1.3927 63 0 0 63 0 0 63 0 0 63 0 0 64 1.15850.81116 64 −0.81116 −1.1585 64 0.81116 −1.1585 64 −1.1585 0.81116 65 0 065 0 0 65 0 0 65 0 0 66 1.4142 0 66 1.4142 0 66 1.4142 0 66 1.4142 0 670 0 67 0 0 67 0 0 67 0 0 68 1.2817 −0.59767 68 0.59767 −1.2817 68−0.59767 −1.2817 68 −1.2817 −0.59767 69 0 0 69 0 0 69 0 0 69 0 0 701.0834 −0.90904 70 1.0834 0.90904 70 1.0834 −0.90904 70 1.0834 0.9090471 0 0 71 0 0 71 0 0 71 0 0

TABLE 17 m₀ = 1 Real Imag m₁ = 15 Real Imag m₂ = 17 Real Imag m₃ = 31Real Imag 0 1 −1 0 1 1 0 1 −1 0 1 1 1 0 0 1 0 0 1 0 0 1 0 0 2 1.0932−0.89717 2 0.89717 −1.0932 2 −0.89717 −1.0932 2 −1.0932 −0.89717 3 0 0 30 0 3 0 0 3 0 0 4 1.3066 −0.5412 4 1.3066 0.5412 4 1.3066 −0.5412 41.3066 0.5412 5 0 0 5 0 0 5 0 0 5 0 0 6 1.4074 0.13862 6 −0.13862−1.4074 6 0.13862 −1.4074 6 −1.4074 0.13862 7 0 0 7 0 0 7 0 0 7 0 0 8 11 8 1 −1 8 1 1 8 1 −1 9 0 0 9 0 0 9 0 0 9 0 0 10 −0.13862 1.4074 10−1.4074 0.13862 10 1.4074 0.13862 10 0.13862 1.4074 11 0 0 11 0 0 11 0 011 0 0 12 −1.3066 0.5412 12 −1.3066 −0.5412 12 −1.3066 0.5412 12 −1.3066−0.5412 13 0 0 13 0 0 13 0 0 13 0 0 14 −0.89717 −1.0932 14 1.09320.89717 14 −1.0932 0.89717 14 0.89717 −1.0932 15 0 0 15 0 0 15 0 0 15 00 16 1 −1 16 1 1 16 1 −1 16 1 1 17 0 0 17 0 0 17 0 0 17 0 0 18 0.897171.0932 18 −10.932 −0.89717 18 1.0932 −0.89717 18 −0.89717 1.0932 19 0 019 0 0 19 0 0 19 0 0 20 −1.3066 0.5412 20 −1.3066 −0.5412 20 −1.30660.5412 20 −1.3066 −0.5412 21 0 0 21 0 0 21 0 0 21 0 0 22 0.13862 −1.407422 1.4074 −0.13862 22 −1.4074 −0.13862 22 −0.13862 −1.4074 23 0 0 23 0 023 0 0 23 0 0 24 1 1 24 1 −1 24 1 1 24 1 −1 25 0 0 25 0 0 25 0 0 25 0 026 −1.4074 −0.13862 26 0.13862 1.4074 26 −0.13862 1.4074 26 1.4074−0.13862 27 0 0 27 0 0 27 0 0 27 0 0 28 1.3066 −0.5412 28 1.3066 0.541228 1.3066 −0.5412 28 1.3066 0.5412 29 0 0 29 0 0 29 0 0 29 0 0 30−1.0932 0.89717 30 −0.89717 1.0932 30 0.89717 1.0932 30 1.0932 0.8971731 0 0 31 0 0 31 0 0 31 0 0

TABLE 18 m₀ = 1 Real Imag m₁ = 15 Real Imag m₂ = 17 Real Imag m₃ = 31Real Imag 32 1 −1 32 1 1 32 1 −1 32 1 1 33 0 0 33 0 0 33 0 0 33 0 0 34−1.0932 0.89717 34 −0.89717 1.0932 34 0.89717 1.0932 34 1.0932 0.8971735 0 0 35 0 0 35 0 0 35 0 0 36 1.3066 −0.5412 36 1.3066 0.5412 36 1.3066−0.5412 36 1.3066 0.5412 37 0 0 37 0 0 37 0 0 37 0 0 38 −1.4074 −0.1386238 0.13862 1.4074 38 −0.13862 1.4074 38 1.4074 −0.13862 39 0 0 39 0 0 390 0 39 0 0 40 1 1 40 1 −1 40 1 1 40 1 −1 41 0 0 41 0 0 41 0 0 41 0 0 420.13862 −1.4074 42 1.4074 −0.13862 42 −1.4074 −0.13862 42 −0.13862−1.4074 43 0 0 43 0 0 43 0 0 43 0 0 44 −1.3066 0.5412 44 −1.3066 −0.541244 −1.3066 0.5412 44 −1.3066 −0.5412 45 0 0 45 0 0 45 0 0 45 0 0 460.89717 1.0932 46 −1.0932 −0.89717 46 1.0932 −0.89717 46 −0.89717 1.093247 0 0 47 0 0 47 0 0 47 0 0 48 1 −1 48 1 1 48 1 −1 48 1 1 49 0 0 49 0 049 0 0 49 0 0 50 −0.89717 −1.0932 50 1.0932 0.89717 50 −1.0932 0.8971750 0.89717 −1.0932 51 0 0 51 0 0 51 0 0 51 0 0 52 −1.3066 0.5412 52−1.3066 −0.5412 52 −1.3066 0.5412 52 −1.3066 −0.5412 53 0 0 53 0 0 53 00 53 0 0 54 −0.13862 1.4074 54 −1.4074 0.13862 54 1.4074 0.13862 540.13862 1.4074 55 0 0 55 0 0 55 0 0 55 0 0 56 1 1 56 1 −1 56 1 1 56 1 −157 0 0 57 0 0 57 0 0 57 0 0 58 1.4047 0.13862 58 −0.13862 −1.4074 580.13862 −1.4074 58 −1.4074 0.13862 59 0 0 59 0 0 59 0 0 59 0 0 60 1.3066−0.5412 60 1.3066 0.5412 60 1.3066 −0.5412 60 1.3066 0.5412 61 0 0 61 00 61 0 0 61 0 0 62 1.0932 −0.89717 62 0.89717 −1.0932 62 −0.89717−1.0932 62 −1.0932 −0.89717 63 0 0 63 0 0 63 0 0 63 0 0

Next, Step S51 or S52 for removing the DC component from the frequencydomain in FIG. 16 will hereinafter be described.

Step S51 is used to perform puncturing of the DC component. Only the DCcomponent in Table 15 is changed to the value of 0. In other words, theresult of Tables 15 and 16 is shown in the following Table 19, and theresult of Tables 17 and 18 is shown in the following Table 20.

For the convenience of description, the following Tables 19 and 20indicate only the DC components, and the remaining components other thanthe DC components are omitted from Tables 19 and 20.

TABLE 19 m₀ = 1 Real Imag m₁ = 17 Real Imag m₂ = 19 Real Imag m₃ = 35Real Imag 0 0 0 0 0 0 0 0 0 0 0 0

TABLE 20 m₀ = 1 Real Imag m₁ = 15 Real Imag m₂ = 17 Real Imag m₃ = 31Real Imag 0 0 0 0 0 0 0 0 0 0 0 0

Step S51 may be explained on the basis of the frequency domain asdescribed above, or may also be explained on the basis of the timedomain.

For example, according to this embodiment of the present invention, thesequence with the length of 35 may be denoted by c(n). This “c(n)”sequence corresponds to the time-domain sequence. The DC-puncturingresult of the “c(n)” sequence may be denoted by “d(n)”.

In this case, the “c(n)” sequence can be represented by

${{c(n)} = {\exp \left( {{- j}\; \pi \; M\frac{n\left( {n + 1} \right)}{35}} \right)}},$

and the “d(n)” sequence can be represented by

$\frac{35}{34}{\left( {{c(n)} - {\sum\limits_{k = 0}^{34}{{c(k)}{\exp \left( {{- j}\; 2\; \pi \; {k \cdot {0/35}}} \right)}}}} \right).}$

If the sequence has the repetition structure in the time domain at stepS52, a frequency component alternately occurs in the frequency indexesof the frequency domain. At step S52, in order to prevent the frequencycomponent from existing in the DC component during the sub-carriermapping, a corresponding sequence is shifted or CS-processed to removethe DC component.

The resultant indexes of Tables 15˜18 are adjusted by the above stepS52, and the detailed result will herein be omitted for the convenienceof description.

After the data process for removing the DC component is completed,another data process S60 for converting the resultant sequence into thetime-domain sequence is conducted. If the result of Table 19 isprocessed by the above step S60, the results of Tables 21 and 22 areacquired. If the result of Table 20 is processed, the results of Tables23 and 24 can be acquired.

TABLE 21 m₀ = 1 Real Imag m₁ = 17 Real Imag m₂ = 19 Real Imag m₃ = 35Real Imag 0 0.88215 0.11785 0 0.88215 0.11785 0 1.1179 0.11785 0 1.11790.11785 1 0.87834 0.030695 1 −0.0307 −0.87834 1 0.030695 −0.87734 1−0.87834 0.030695 2 0.82184 −0.22417 2 0.82184 0.45987 2 1.0575 −0.224172 1.0575 0.45987 3 0.58926 −0.58926 3 0.58926 −0.58926 3 −0.58926−0.58926 3 −0.58926 −0.58926 4 0.055797 −0.86696 4 0.055797 1.1027 40.2915 −0.86696 4 0.2915 1.1027 5 −0.69143 −0.7013 5 0.7013 0.69143 5−0.7013 0.69143 5 0.69143 −0.7013 6 −1.1179 0.11785 6 −1.1179 0.11785 6−0.88215 0.11785 6 −.088215 0.11785 7 −0.54047 1.0242 7 −1.0242 0.540477 1.0242 0.54047 7 0.54047 1.0242 8 0.64819 0.76064 8 0.64819 −0.52494 80.8839 0.76064 8 0.8839 −0.52494 9 0.58926 −0.58926 9 0.58926 −0.58929 9−0.58926 −0.58926 9 −0.58926 −0.58926 10 −0.8839 −0.52494 10 −0.88390.76064 10 −0.64819 −0.52494 10 −0.64819 0.76064 11 −0.54047 1.0242 11−1.0242 0.54047 11 1.0242 0.4047 11 0.54047 1.0242 12 0.88215 0.11785 120.88215 0.11785 12 1.1179 0.11785 12 1.1179 0.11785 13 −0.69143 −0.701313 0.7013 0.69143 13 −0.7013 0.69143 13 0.69143 −0.7013 14 −0.29151.1027 14 −0.2915 −0.86696 14 −0.0558 1.1027 14 −0.0558 −0.86696 150.58926 −0.58926 15 0.58926 −0.58926 15 −0.58926 −0.58926 15 −0.58926−0.58926 16 −1.0575 0.45987 16 −1.0575 −0.22417 16 −0.82184 0.45987 16−0.82184 −0.22417 17 0.87734 0.030695 17 −0.0307 −0.87834 17 0.030695−0.87834 17 −0.87834 0.030695 18 −1.1179 0.11785 18 −1.1179 0.11785 18−0.88215 0.11785 18 −0.88215 0.11785 19 0.87834 0.030695 19 −0.0307−0.87834 19 0.030695 −0.87834 19 −0.87834 0.030695 20 −1.0575 0.45987 20−1.0575 −0.22417 20 −0.82184 0.45987 20 −0.82184 −0.22417 21 0.58926−0.58926 21 0.58926 −0.58926 21 −0.58926 −0.58926 21 −0.58926 −0.5892622 −0.2915 1.1027 22 −0.2915 −0.86696 22 −0.0558 1.1027 22 −0.0558−0.86696 23 −0.69143 −0.7013 23 0.7013 0.69143 23 −0.7013 0.69143 230.69143 −0.7013 24 0.88215 0.11785 24 0.88215 0.11785 24 1.1179 0.1178524 1.1179 0.11785 25 −0.54047 1.0242 25 −1.0242 0.54047 25 1.02420.54047 25 0.54047 1.0242 26 −0.8839 −0.52494 26 −0.8839 0.76064 26−0.64819 −0.52494 26 −0.64819 0.76064 27 0.5926 −0.58926 27 0.58926−0.58926 27 −0.58926 −0.58926 27 −0.58926 −0.58926 28 0.64819 0.76064 280.64819 −0.52494 28 0.8839 0.76064 28 0.8839 −0.52494 29 −0.54047 1.024229 −1.0242 0.54047 29 1.0242 0.54047 29 0.54047 1.0242 30 −1.11790.11785 30 −1.1179 0.11785 30 −0.88215 0.11785 30 −0.88215 0.11785 31−0.69143 −0.7013 31 0.7013 0.69143 31 −0.7013 0.69143 31 0.69143 −0.701332 0.055797 −0.86696 32 0.055797 1.1027 32 0.2915 −0.86696 32 0.29151.1027 33 0.58926 −0.58926 33 0.58926 −0.58926 33 −0.58926 −0.58926 33−0.58926 −0.58926 34 0.82184 −0.22417 34 0.82184 0.45987 34 1.0575−0.22417 34 1.0575 0.45987 35 0.87834 0.030695 35 −0.0307 −0.87834 350.030695 −0.87834 35 −0.87834 0.030695

TABLE 22 m₀ = 1 Real Imag m₁ = 17 Real Imag m₂ = 19 Real Imag m₃ = 35Real Imag 36 0.88215 0.11785 36 0.88215 0.11785 36 1.1179 0.11785 361.1179 0.11785 37 0.87834 0.030695 37 −0.0307 −0.87834 37 0.030695−0.87834 37 −0.87834 0.030695 38 0.82184 −0.22417 38 0.82184 0.45987 381.0575 −0.22417 38 1.0575 0.45987 39 0.58926 −0.58926 39 0.58926−0.58926 39 −0.58926 −0.58926 39 −0.58926 −0.58926 40 0.055797 −0.8669640 0.055797 1.1027 40 0.2915 −0.86696 40 0.2915 1.1027 41 −0.691430.7013 41 0.7013 0.69143 41 −0.7013 0.69143 41 0.69143 −0.7013 42−1.1179 0.11785 42 −1.1179 0.11785 42 −0.88215 0.11785 42 −0.882150.11785 43 −0.54047 1.0242 43 −1.0242 0.54047 43 1.0242 0.54047 430.54047 1.0242 44 0.64819 0.76064 44 0.64819 −0.52494 44 0.8839 0.7606444 0.8839 −0.52494 45 0.58926 −0.58926 45 0.58926 −0.58926 45 −0.58926−0.58926 45 −0.58926 −0.58926 46 −0.8839 −0.52494 46 −0.8839 0.76064 46−0.64819 −0.52494 46 −0.64819 0.76064 47 −0.54047 1.0242 47 −1.02420.54047 47 1.0242 0.54047 47 0.54047 1.0242 48 0.88215 0.11785 480.88215 0.11785 48 1.1179 0.11785 48 1.1179 0.11785 49 −0.69143 −0.701349 0.7013 0.69143 49 −0.7013 0.69143 49 0.69143 −0.7013 50 −0.29151.1027 50 −0.2915 −0.86696 50 −0.0558 1.1027 50 −0.0558 −0.86696 510.58926 −0.58926 51 0.58926 −0.58926 51 −0.58926 −0.58926 51 −0.58926−0.58926 52 −1.0575 0.45987 52 −1.0575 −0.22417 52 −0.82184 0.45987 52−0.82184 −0.22417 53 0.87834 0.030695 53 −0.0307 −0.87834 53 0.030695−0.87834 53 −0.87834 0.030695 54 −1.1179 0.11785 54 −1.1179 0.11785 54−0.88215 0.11785 54 −0.88215 0.11785 55 −0.87834 0.030695 55 −0.0307−0.87834 55 0.030695 −0.87834 55 −0.87834 0.030695 56 −1.0575 0.45987 56−1.0575 −0.22417 56 −0.82184 0.45987 56 −0.82184 −0.22417 57 0.58926−0.58926 57 0.58926 −0.58926 57 −0.58926 −0.58926 57 −0.58926 −0.5892658 −0.2915 1.1027 58 −0.2915 −0.86696 58 −0.0558 1.1027 58 −0.0558−0.86696 59 −0.69143 −0.7013 59 0.7013 0.69143 59 −0.7013 0.69143 590.69143 −0.7013 60 0.88215 0.11785 60 0.88215 0.11785 60 1.1179 0.1178560 1.1179 0.11785 61 −0.54047 1.0242 61 −1.0242 0.54047 61 1.02420.54047 61 0.54047 1.0242 62 −0.8839 −0.52494 62 −0.8839 0.76064 62−0.64819 −0.52494 62 −0.64819 0.76046 63 0.58926 −0.58926 63 0.58926−0.58926 63 −0.58926 −0.58926 63 −0.58926 −0.58926 64 0.64819 0.76064 640.64819 −0.52494 64 0.8839 0.76064 64 0.8839 −0.52494 65 −0.54047 1.024265 −1.0242 0.54047 65 1.0242 0.54047 65 0.54047 1.0242 66 −1.11790.11785 66 −1.1179 0.11785 66 −0.88215 0.11785 66 −0.88215 0.11785 67−0.69143 −0.7013 67 0.7013 0.69143 67 −0.7013 0.69143 67 0.69143 −0.701368 0.55797 −0.86696 68 0.055797 1.1027 68 0.2915 −0.86696 68 0.29151.1027 69 0.58926 −0.58926 69 0.58926 −0.58926 69 −0.58926 −0.58926 69−0.58926 −0.58926 70 0.82184 −0.22417 70 0.82184 0.45987 70 1.0575−0.22417 70 1.0575 0.45987 71 0.87834 0.030695 71 −0.0307 −0.87834 710.030695 −0.87834 71 −0.87834 0.030695

TABLE 23 m₀ = 1 Real Imag m₁ = 15 Real Imag m₂ = 17 Real Imag m₃ = 31Real Imag 0 0.875 0.125 0 0.875 −0.125 0 0.875 0.125 0 0.875 −0.125 10.87018 0.026983 1 −0.02698 −1.1202 1 −0.22302 −0.87018 1 −1.1202−0.22302 2 0.79888 −0.25768 2 0.79888 0.25768 2 0.79888 −0.25768 20.79888 0.25768 3 0.50939 −0.64801 3 0.64801 −0.75939 3 −0.89801−0.50939 3 −0.75939 −0.89801 4 −0.125 −0.875 4 −0.125 0.875 4 −0.125−0.875 4 −0.125 0.875 5 −0.89801 −0.50939 5 0.50939 0.64801 5 −0.075390.89801 5 0.64801 −0.75939 6 −1.0489 0.50768 6 −1.0489 −0.50768 6−1.0489 0.50768 6 −1.0489 −0.50768 7 −0.02698 1.1202 7 −1.1202 −0.223027 0.87018 0.026983 7 −0.22302 0.87018 8 0.875 0.125 8 0.875 −0.125 80.875 0.125 8 0.875 −0.125 9 −0.22302 −0.87018 9 0.87018 −0.02698 9−1.1202 0.22302 9 −0.02698 −1.1202 10 −1.0489 0.50768 10 −1.0489−0.50768 10 −1.0489 0.50768 10 −1.0489 −0.50768 11 0.64801 0.75939 11−0.75939 −0.89801 11 0.50939 −0.64801 11 −0.89801 0.50939 12 −0.125−0.875 12 −0.125 0.875 12 −0.125 −0.875 12 −0.125 0.875 13 −0.759390.89801 13 −0.89801 0.50939 13 0.64801 0.75939 13 0.50939 0.64801 140.79888 −0.25768 14 0.79888 0.25768 15 0.79888 −0.25768 14 0.798880.25768 15 −1.1202 0.22302 15 −0.22302 0.87018 15 −0.02698 1.1202 150.87015 −0.02698 16 0.875 0.125 16 0.875 −0.125 16 0.875 0.125 16 0.875−0.125 17 −1.1202 0.22302 17 −0.22302 0.87018 17 −0.02698 1.1202 170.87018 −0.02698 18 0.79888 −0.25768 18 0.79888 0.25768 18 0.798880.25768 18 0.79888 0.25768 19 −0.75939 0.89801 19 −0.89801 0.50939 190.64801 0.75939 19 0.50939 0.64801 20 −0.125 −0.875 20 −0.125 0.875 20−0.125 −0.875 20 −0.125 0.875 21 0.64801 0.75939 21 −0.75939 −0.89801 210.50939 −0.64801 21 −0.89801 0.50939 22 −1.0489 0.50768 22 −1.0489−0.50768 22 −1.0489 0.50768 22 −1.0489 −0.50768 23 −0.22302 −0.87018 230.87018 −0.02698 23 −1.1202 0.22302 23 −0.02698 −1.1202 24 0.875 0.12524 0.875 −0.125 24 0.875 0.125 24 0.875 −0.125 25 −0.02698 1.1202 25−1.1202 −0.22302 25 0.87018 0.026983 25 −0.22302 0.87018 26 −1.04890.50768 26 −1.049 −0.50768 26 −1.0489 0.50768 26 −1.0489 −0.50768 27−0.89801 −0.50939 27 0.50939 0.67801 27 −0.75939 0.89801 27 0.64801−0.75939 28 −0.125 −0.875 28 −0.125 0.875 28 −0.125 −0.875 28 −0.1250.875 29 0.50939 −0.64801 29 0.64801 −0.75939 29 −0.89801 −0.50939 29−0.75939 −0.89801 30 0.79888 −0.25768 30 0.79888 0.25768 30 0.79888−0.25768 30 0.79888 0.25768 31 0.87018 0.026983 31 −0.02698 −1.1202 31−0.22302 −0.87018 31 −1.1202 −0.22302

TABLE 24 m₀ = 1 Real Imag m₁ = 15 Real Imag m₂ = 17 Real Imag m₃ = 31Real Imag 32 0.875 0.125 32 0.875 −0.125 32 0.875 0.125 32 0.875 −0.12533 0.87018 0.026983 33 −0.02698 −1.1202 33 −0.22302 −0.87018 33 −1.1202−0.22302 34 0.79888 −0.25768 34 0.79888 0.25768 34 0.79888 −0.25768 340.79888 0.25768 35 0.50939 −0.64801 35 0.64801 −0.75939 35 −0.98901−0.50939 35 −0.75939 −0.89801 36 −0.125 −0.875 36 −0.125 0.875 39 −0.125−0.875 36 −0.125 0.875 37 −0.89801 −0.50939 37 0.50939 0.64801 37−0.75939 0.89801 37 0.64801 −0.75939 38 −1.0489 0.50768 38 −1.0489−0.50768 38 −1.0489 0.50768 38 −1.0489 −0.50768 39 −0.02698 1.1202 39−1.1202 −0.22302 39 0.87018 0.026983 39 −0.22302 0.87018 40 0.875 0.12540 0.875 −0.125 40 0.875 0.125 40 0.875 −0.125 41 −0.22302 0.87018 410.87018 −0.02698 41 −1.1202 0.22302 41 −0.02698 −1.1202 42 −1.04890.50768 42 −1.0489 −0.50768 42 −1.0489 0.50768 42 −1.0489 −0.50768 430.64801 0.75939 43 −0.75939 −0.89801 43 0.50939 −0.64801 43 −0.898010.50939 44 −0.125 −0.875 44 −0.125 0.875 44 −0.125 −0.875 44 −0.1250.875 45 −0.75939 0.89801 45 −0.89801 0.50939 45 0.64801 0.75939 450.50939 0.64801 46 0.79888 −0.25768 46 0.79888 0.25768 46 0.79888−0.25768 46 0.79888 0.25768 47 −1.1202 0.22302 47 −0.22302 0.87018 47−0.02698 1.1202 47 0.87018 −0.02698 48 0.875 0.125 48 0.875 −0.125 480.875 0.125 48 0.875 −0.125 49 −1.1202 0.22302 49 −0.22302 0.87018 49−0.02698 1.1202 49 0.87018 −0.02698 50 0.79888 −0.25768 50 0.798880.25768 50 0.79888 −0.25768 50 0.79888 0.25768 51 −0.75939 0.89801 51−0.89801 0.50939 51 0.64801 0.75939 51 0.50939 0.64801 52 −0.125 −0.87552 −0.125 0.875 52 −0.125 −0.875 52 −0.125 0.875 53 0.64801 0.75939 53−0.75939 −0.89801 53 0.50939 −0.64801 53 −0.89801 0.50939 54 −1.04890.50768 54 −1.0489 −0.50768 54 −1.0489 0.50768 54 −1.0489 −0.50768 55−0.22302 −0.87018 55 0.87018 −0.02698 55 −1.1202 0.22302 55 −0.02698−1.1202 56 0.875 0.125 56 0.875 −0.125 56 0.875 0.125 56 0.875 −0.125 57−0.02698 1.1202 57 −1.1202 −0.22302 57 0.87018 0.026983 57 −0.223020.87018 58 −1.0489 0.50768 58 −1.0489 −0.50768 58 −1.0489 0.50768 58−1.0489 −0.50768 59 −0.89801 −0.50939 59 0.50939 0.64801 59 −0.759390.89801 59 0.64801 −0.75939 60 −0.125 −0.875 60 −0.125 0.875 60 −0.125−0.875 60 −0.125 0.875 61 0.50939 −0.64801 61 0.64801 −0.75939 61−0.89801 −0.50939 61 −0.75939 −0.89801 62 0.79888 −0.25768 62 0.798880.25768 62 0.79888 −0.25768 62 0.79888 0.25768 63 0.87018 0.026983 63−0.02698 −1.1202 63 −0.222302 −0.87018 63 −1.1202 −0.22302

FIG. 17 shows the comparison in constellation map between a sequencehaving no DC component and the other sequence having the DC componentaccording to the present invention.

In more detail, if the mother sequence index (m₀) is “1”, the2×-repetition result of the sequence with the length of 36 is shown inFIG. 17(a), and the 2×-repetition result of the sequence with the lengthof 32 is shown in FIG. 17(b).

In this case, each of the above-mentioned two cases FIG. 17(a) and FIG.17(b) includes only 12 constellations. Although the DC puncturing isperformed, the constellation location is shifted by the punctured value,so that 12 fixed constellations are maintained.

The above-mentioned characteristics with the less number ofconstellations can greatly reduce the number of calculations associatedwith the correlation function of the reception end.

FIG. 18 is a conceptual diagram illustrating a method for designing asequence in a frequency domain so that the 2×-repetition structure in atime domain is formed according to the present invention.

The Zadoff-Chu sequence maintains ideal correlation characteristics inthe time domain and the frequency domain. Therefore, the sequence may begenerated in the time domain, or may also be generated in the frequencydomain.

In other words, if the Zadoff-Chu sequence is inserted into thefrequency domain, and the sequence is inserted into the even-thfrequency index at intervals of two partitions (i.e., two spaces), thereis acquired the same result as in the above case in which the sequencegenerated in the time domain is mapped to the time domain.

Additional description of the step S10 of FIG. 16 will hereinafter bedescribed. The method for selecting multiple sequence indexes is equalto a method for easily calculating the cross-correlation using thereception end.

However, the Zadoff-Chu sequence basically serves as the polyphasesequence, so that it is vulnerable to the frequency offset.

Therefore, it is preferable that the sequence may be selected inconsideration of the frequency offset in the sequence selection step.

In other words, if three sequences are selected without consideration ofthe frequency offset according to Equation 18, the present invention mayhave difficulty in searching for a correct correlation value accordingto the frequency offset. In this case, two sequence indexes from amongthree sequence indexes may be decided by Equation 18, and the remainingone sequence index may be decided in consideration of thefrequency-offset characteristics.

In conclusion, in the case of selecting a plurality of sequence indexes,only Equation 18 may be considered, and the frequency-offsetcharacteristics may also be considered along with Equation 18.

The above-mentioned concept relates to a plurality of sequence indexesin consideration of the frequency offset. A method for additionallyconsidering other criterions other than the frequency offset willhereinafter be described.

Next, a method for considering the sequence index in additionallyconsidering the correlation characteristics will hereinafter bedescribed.

For example, the Zadoff-Chu sequence serves as a CAZAC sequence, so thatit is preferable that a specific sequence having ideal auto-correlationcharacteristics and superior cross-correlation characteristics may beselected. For example, if the length is 35, the set of three sequences(1, 2, 34) or (1, 33, 34) may be selected in consideration of Equation19, the frequency-offset characteristics, and the PAPR characteristics.

The cross-correlation characteristics of the index set (1, 2, 34) isshown in FIG. 19.

Next, the characteristics of the sequence with the length of 35according to the present invention will hereinafter be described.

Preferably, the sequence with the length 35 may be used for the LTEsystem.

It is assumed that the SCH signal is transferred to six radio blocks(corresponding to 73 sub-carriers including the DC component).

If the 2×-repetition structure is made in the time domain using the 73sub-carriers, the sequence with the length 36 can be used. All the casesof the frequency or time domain can be made available. For example,although the sequence is not repeated in the time domain or is repeatedthree times, all the cases of the frequency or time domain can also bemade available.

In this case, the present invention requires the reception end of the(1.08×MHz) interpolator.

However, based on the above-mentioned criterions (i.e., references), anoptimum index group is (1, 2, 35). In this case, the cross-correlationis shown in FIG. 20.

If the worst happens, the index group of FIG. 20 may have thecross-correlation of 40%.

In this case, it is preferable that the present invention may use asequence with the length shorter than “36”.

In this case, it is preferable that the present invention approaches adesired length to be originally generated and at the same time selectsthe odd-length sequence, so that it is more preferable that the lengthmay be set to 35.

The sequence with the length of 35 may search for the set havingcorrelation characteristics superior to those of the even-lengthsequence.

For reference, the selection of the sequence index (1,2,34) in FIGS. 19and 20 relates to the 2×-repetition of the sequence.

When the PSC for the P-SCH is generated, the present invention may use acorresponding sequence without repetition of the sequence aftergenerating the sequence.

It is assumed that the present invention uses three Zadoff-Chu sequencesas multiple sequences for the PSC. In this case, the present inventionmust select two root indexes from among three Zadoff-Chu sequences sothat the sum of the two root indexes satisfies “63” in the case of usingthe sequence with the length 63. As a result, the conjugate symmetryproperty between corresponding sequences can be satisfied.

And, the remaining one root index other than the two root indexes may beselected using other conditions, and it is preferable that the remainingone root index may be selected in consideration of the above-mentionedfrequency offset problem (and/or PAPR (CM)).

Under the above-mentioned assumption, if the frequency-offsetsensitivity and/or the PAPR degree for each root index are(is) expressedaccording to a variety of conditions, the following result can beacquired.

FIG. 21 is a graph illustrating the frequency-offset sensitivity and theCM under a variety of conditions according to the present invention.

Referring to FIG. 21, “Nzc” is indicative of the length of theZadoff-Chu (ZC) sequence. Case 1 indicates that the ZC sequence with thelength 63 is used. Case 2 indicates that the ZC sequence with the length63 is used according to the circular-extending scheme.

Case 3 indicates that the ZC sequence with the length 64 is used. Case 4indicates that the ZC sequence with the length 64 is used by a truncatedscheme.

In more detail, FIG. 21(a) shows the frequency-offset sensitivity of theabove-mentioned cases 1˜4, and FIG. 21(b) shows the CM of each of theaforementioned cases 1˜4.

Based on the above-mentioned result, the present invention provides amethod for selecting the root index set as shown in the following Table25.

TABLE 25 Case 1 Case 2 Case 3 Case 4 Root 34 29 25 34 29 25 29 31 27 3134 38 index FO  0.20204  0.20204  0.22885  0.18631  0.18631  0.21613 0.37447  0.37564  0.38151  0.16547  0.16547  0.17942 sensi- tivity Raw 2.2763  2.2763  2.3062  2.2318  2.2318  2.2179  2.9416  4.6762  4.2103 4.2067  4.2067  2.6442 CM [dB] Mean 0.015622 0.015569 0.015185 0.015019value of cross- corel- ation Root O O X O sym- metry with 0.96 MHz samp-ling rate

In other words, if the root index of the first sequence, the root indexof the second sequence, and the root index of the third sequence aredenoted by (x,y,z), (34,29,25) is selected under the Case 1, and(34,29,25) is selected under the Case 2. In the meantime, (29, 31, 27)is selected under the Case 3, and (31, 34, 38) is selected under theCase 4. Except for the root-index set of the Case 3 from among theroot-index sets, all the sets, each of which has the above-mentionedconjugate symmetry property, are contained in the sequence selectionprocess.

When the selected root-index set is used as described above, theauto-correlation profile is as follows.

FIGS. 22˜25 are graphs illustrating auto-correlation profiles of theindividual sets when a root-index set is selected according to thepresent invention;

In FIGS. 22˜25, it is assumed that the 1-part correlation indicates thefrequency offset situation of 0.1 ppm, and the 2-part correlationindicates the frequency offset situation of 5.0 ppm. In the case ofusing the root-index set according to the present invention, it can berecognized that the superior auto-correlation characteristics can beacquired.

In the meantime, a method for transmitting the signal using sequencesgenerated when the root-index set of Case 1 and the ZC sequence with thelength of 63 are used will hereinafter be described. In this case, inthe root-index set of Case 1, the root index of the first sequence is34, the root index of the second sequence is 29, and the root index ofthe third sequence is 25.

If “34”, “29”, and “25” are used as the root indexes of three sequencecombinations, the sum of the root index “34” and “29” is 63corresponding to the length of the corresponding ZC sequence, so thatthe above-mentioned conjugate symmetry property is satisfied. Therefore,if the sequence generated by the above root indexes is transmitted as acommunication signal, the reception end can easily calculate thecross-correlation operation using the generated sequence.

In the meantime, provided that either one of root indexes from among theabove-mentioned root-index set is selected so that the sequence with thelength 62 is generated, a method for mapping the generated sequence tothe frequency-domain resource element will hereinafter be described.

FIG. 26 is a conceptual diagram illustrating a method for mapping thesequence with the length of 63 to a frequency-domain resource elementaccording to the present invention.

After the sequence with the length 63 is generated, the presentinvention continuously maps the generated sequence to the frequencyresource element in order to maintain the ZC-sequence characteristics,as much as possible, indicating that the ZC sequence has a constantamplitude in the time and frequency domains, and a detailed descriptionthereof will hereinafter be described.

As can be seen from FIG. 26, in the Zadoff-Chu (ZC) sequence with thelength of 63, components corresponding to “P(0)˜P(30)” are continuouslymapped to resource elements from a frequency resource element with afrequency resource element index of “−31” to a frequency resourceelement with a frequency resource element index of “−1”, and componentscorresponding to “P(32)˜P(62)” are continuously mapped to resourceelements from a frequency resource element with a frequency resourceelement index of “1” to a frequency resource element with a frequencyresource element index of “31”. Under the above-mentioned mappingoperation, the 32-th element (i.e., P(31)) of the generated sequence ismapped to the part of the frequency “0”.

Therefore, this embodiment provides a method for puncturing the “P(31)”part mapped to the part having the frequency “0” as shown in FIG. 26.However, if required, the present invention may also use another methodcapable of puncturing the part having the frequency “0” during thetime-domain transmission.

The sequence mapped to the frequency domain may be converted into thetime-domain signal by the IFFT or equivalent operation (e.g., IDFT orIFT), so that it may also be transmitted as the OFDM symbol signal.

The signal transmitted by the above-mentioned embodiments may bereceived in the reception end, so that the reception end may detect acorresponding signal using the cross-correlation operation. In thiscase, in the case of using the sequence set having the above-mentionedconjugate symmetry property, the reception end can more easily detectthe signal.

Next, the signal detection process of the reception end, i.e. a methodfor calculating the cross-correlation value, will hereinafter bedescribed.

The Aspect of Reception End

Operations of the reception end will hereinafter be described.

There is a predetermined rule among the Tx sequences generated by theabove-mentioned embodiments. So, the reception end can acquire thecorrelation values of sequences corresponding to the remainingroot-sequence indexes using a correlation value of a specific sequencecorresponding to a single root-sequence index, instead of calculatingthe cross-correlation value of all the sequences.

A method for calculating the cross-correlation value according to thisembodiment will hereinafter be described. This embodiment calculates thecross-correlation value between the Rx signal and each of the multiplesequences. In this case, the present invention determines severalintermediate values generated while the cross-correlation value betweenthe Rx signal and the specific sequence (i.e., the first sequence) iscalculated. And, the present invention can calculate not only thecross-correlation value between the Rx signal and the first sequence bythe addition or subtraction of the intermediate values, but also anothercross-correlation value between the Rx signal and another sequence(i.e., a second sequence).

A variety of cases in which multiple available sequences are selectedwill be described in detail.

<Case 1>

This example shows a method for calculating the cross-correlation valueof the selected sequences, which have the length of 36 and the valuesm₀=1, m₁=17, m₂=19, m₃=35.

The reception end stores the sequence having a sequence index of “1”,and calculates the cross-correlation value between the stored sequenceand the received sequence. In this case, in the case of using theintermediate results generated when the cross-correlation value betweenthe Rx signal and the sequence having a sequence index “1” iscalculated, the cross-correlation value between the Rx signal and thesequence having the sequence index “17” can be calculated, thecross-correlation value between the Rx signal and the sequence havingthe sequence index “19” can be calculated, and at the same time thecross-correlation value between the Rx signal and the sequence havingthe sequence index “35” can be calculated,

This example will be described on the basis of a specific case in whichthe cross-correlation value of the τ-th delay is calculated. In otherwords, if the Rx signal is denoted by r(n), this example will bedescribed on the basis of the cross-correlation value associated withthe d-th delayed sample r(n+d).

In this case, the result of the correlation value of the sequence index“m” is shown in the following equation 22:

$\begin{matrix}{{R^{m}(d)} = {\frac{1}{L\; N}{\sum\limits_{n = 0}^{{L\; N} - 1}{{r\left( {n + d} \right)}\left( {a^{m}(n)} \right)^{*}}}}} & \left\lbrack {{Equation}\mspace{14mu} 22} \right\rbrack\end{matrix}$

where m₀=1, m₁=17, m₂=19, and m₃=35, so that the following relationshipcan be provided.

$\begin{matrix}{{a^{{m\; 0} = 1}(k)} = {\exp\left( {{- j}\; {\pi \cdot 1 \cdot \frac{k^{2}}{36}}} \right)}} & \left\lbrack {{Equation}\mspace{14mu} 23} \right\rbrack \\\begin{matrix}{{a^{{m\; 1} = 17}(k)} = {\exp\left( {{- j}\; {\pi \cdot 17 \cdot \frac{k^{2}}{36}}} \right)}} \\{= {\exp\left( {{- j}\; {\pi \cdot \left( {18 - 1} \right) \cdot \frac{k^{2}}{36}}} \right)}} \\{= {\exp \left( {- {j\left( {{\frac{\pi}{2}k^{2}} - {\frac{\pi}{36}k^{2}}} \right)}} \right)}} \\{= \left\{ \begin{matrix}{\left( {a_{even}^{{m\; 0} = 1}(k)} \right)^{*},} & {{when}\mspace{14mu} k\mspace{14mu} {is}\mspace{14mu} {even}} \\{{{- j} \cdot \left( {a_{odd}^{{m\; 0} = 1}(k)} \right)^{*}},} & {otherwise}\end{matrix} \right.}\end{matrix} & \; \\\begin{matrix}{{a^{{m\; 2} = 19}(k)} = {\exp\left( {{- j}\; {\pi \cdot 19 \cdot \frac{k^{2}}{36}}} \right)}} \\{= {\exp\left( {{- j}\; {\pi \cdot \left( {18 + 1} \right) \cdot \frac{k^{2}}{36}}} \right)}} \\{= {\exp \left( {- {j\left( {{\frac{\pi}{2}k^{2}} + {\frac{\pi}{36}k^{2}}} \right)}} \right)}} \\{= \left\{ \begin{matrix}{{a_{even}^{{m\; 0} = 1}(k)},} & {{when}\mspace{14mu} k\mspace{14mu} {is}\mspace{14mu} {even}} \\{{{- j} \cdot {a_{odd}^{{m\; 0} = 1}(k)}},} & {otherwise}\end{matrix} \right.}\end{matrix} & \; \\\begin{matrix}{{a^{{m\; 3} = 35}(k)} = {\exp\left( {{- j}\; {\pi \cdot 35 \cdot \frac{k^{2}}{36}}} \right)}} \\{= {\exp\left( {{- j}\; {\pi \cdot \left( {36 - 1} \right) \cdot \frac{k^{2}}{36}}} \right)}} \\{= {\exp \left( {- {j\left( {{\pi \; k^{2}} - {\frac{\pi}{36}k^{2}}} \right)}} \right)}} \\{= \left\{ \begin{matrix}{\left( {a_{even}^{{m\; 0} = 1}(k)} \right)^{*},} & {{when}\mspace{14mu} k\mspace{14mu} {is}\mspace{14mu} {even}} \\{{- \left( {a_{odd}^{{m\; 0} = 1}(k)} \right)^{*}},} & {otherwise}\end{matrix} \right.}\end{matrix} & \;\end{matrix}$

In addition, a^(m1=17)(k) is indicative of a conjugate of a^(m0=1)(k) onthe condition that the “k” value is an even number. If the “k” value isan odd number, the real part of a^(m0=1)(k) is replaced with theimaginary part of the same, and the replaced result is multiplied by thevalue “−1”.

Also, a^(m2=19)(k) is indicative of a conjugate of a^(m0=1)(k) on thecondition that the “k” value is an even number. If the “k” value is anodd number, a^(m2=19)(k) is indicative of a conjugate of the resultacquired when the real part is replaced with the imaginary part.

a^(m3=35)(k) is acquired when the value “−1” is multiplied by only thereal part of a^(m0=1)(k) on the condition that the “k” value is an evennumber. If the “k” value is an odd number, a^(m3=35)(k) is equal to aconjugate symmetry property of a^(m0=1)(k).

The Rx signal r(k+d) can be calculated using an instantaneouscorrelation value of each sequence in association with“r_i(k+d)+jr_q(k+d)”. In this case, “r_i( )” is indicative of a realpart of the Rx signal, and the “r_q( )” is indicative of an imaginarypart of the Rx signal.

For the convenience of description, the cross-correlation value of theRx signal (i.e., the cross-correlation value between the Rx signal andthe known sequence of the reception end) can be defined as follows.

For the convenience of description, the cross-correlation valueΣr(2l+d)(a^(m0=1)(2l))* between the known sequence of the reception endand the even-th sequence of the Rx signal is divided into a real partand an imaginary part, as represented by the following equation 24:

$\begin{matrix}{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + d} \right)}\left( {a^{{m\; 0} = 1}\left( {2l} \right)} \right)^{*}}} = {{\left( {{{Reven\_ i}{\_ i}} + {{Reven\_ q}{\_ q}}} \right) + {j\left( {{{- {Ieven\_ i}}{\_ q}} + {{Ieven\_ q}{\_ i}}} \right)}} = {{Reven}^{0} + {jIeven}^{0}}}} & \left\lbrack {{Equation}\mspace{14mu} 24} \right\rbrack\end{matrix}$

The result of Equation 24 may be divided into a real part (hereinafterreferred to as “Reven(0)” and an imaginary part (hereinafter referred toas “Ieven(0)”.

If the cross-correlation value associated with the odd-th sequence ofthe Rx signal is divided into a real part and an imaginary part, thefollowing equation 25 can be acquired:

$\begin{matrix}{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + 1 + d} \right)}\left( {a^{{m\; 0} = 1}\left( {{2l} + 1} \right)} \right)^{*}}} = {{\left( {{{Rodd\_ i}{\_ i}} + {{Rodd\_ q}{\_ q}}} \right) + {j\left( {{{- {Iodd\_ i}}{\_ q}} + {{Iodd\_ q}{\_ i}}} \right)}} = {{Rodd}^{\mspace{11mu} 0} + {jIodd}^{\mspace{11mu} 0}}}} & \left\lbrack {{Equation}\mspace{14mu} 25} \right\rbrack\end{matrix}$

The result of Equation 25 may be divided into a real part (hereinafterreferred to as “Rodd(0)” and an imaginary part (hereinafter referred toas “Iodd(0)”.

If the cross-correlation value Σr(2l+d)(a^(m0=1)(2l)) associated withthe even-th sequence of the Rx signal's conjugate is divided into a realpart and an imaginary part, the following equation 26 can be acquired:

$\begin{matrix}{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + d} \right)}{a^{{m\; 0} = 1}\left( {2l} \right)}}} = {{\left( {{{Reven\_ i}{\_ i}} - {{Reven\_ q}{\_ q}}} \right) + {j\left( {{{Ieven\_ i}{\_ q}} + {{Ieven\_ q}{\_ i}}} \right)}} = {{Reven}^{1} + {jIeven}^{1}}}} & \left\lbrack {{Equation}\mspace{14mu} 26} \right\rbrack\end{matrix}$

The result of Equation 26 may be divided into a real part (hereinafterreferred to as “Reven(1)” and an imaginary part (hereinafter referred toas “Ieven(1)”.

If the cross-correlation value Σr(2l+1+d)(a^(m0=1)(2l+1)) associatedwith the odd-th sequence of the Rx signal's conjugate is divided into areal part and an imaginary part, the following equation 27 can beacquired:

$\begin{matrix}{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + 1 + d} \right)}{a^{{m\; 0} = 1}\left( {{2l} + 1} \right)}}} = {{\left( {{{Rodd\_ i}{\_ i}} - {{Rodd\_ q}{\_ q}}} \right) + {j\left( {{{Iodd\_ i}{\_ q}} + {{Iodd\_ q}{\_ i}}} \right)}} = {{Rodd}^{\mspace{11mu} 1} + {jIodd}^{\mspace{11mu} 1}}}} & \left\lbrack {{Equation}\mspace{14mu} 27} \right\rbrack\end{matrix}$

The result of Equation 27 may be divided into a real part (hereinafterreferred to as “Rodd(1)” and an imaginary part (hereinafter referred toas “Iodd(1)”.

In this case, the calculation of the values “Reven0”, “Ieven0”, “Rodd0”,“Iodd0”, “Reven1”, “Ieven1”, “Rodd1”, and “Iodd1” may be considered tobe equal to the calculation of the values “Reven_i_i”, “Revenq_q”,“Ieven_i_q”, “Ieven_q_i”, “Rodd_i_i”, “Rodd_q_q”, “Iodd_i_q”, and“Iodd_q_i” shown in Equations 24˜27.

The method for calculating the above-mentioned values “Reven_i_i”,“Revenq_q”, “Ieven_i_q”, “Ieven_q_i”, “Rodd_i_i”, “Rodd_q_q”,“Iodd_i_q”, and “Iodd_q_i” will hereinafter be described with referenceto the following equation 28:

$\begin{matrix}{{{{{Reven\_ i}{\_ i}} = {{{{r\_ i}\left( {0 + d} \right)*1} + {{r\_ i}\left( {2 + d} \right)*0.93969} + {{r\_ i}\left( {4 + d} \right)*0.17365} + {{r\_ i}\left( {6 + d} \right)*\left( {- 1} \right)} + {{r\_ i}\left( {8 + d} \right)*0.76604} + {{r\_ i}\left( {10 + d} \right)*\left( {- 0.76604} \right)} + {{r\_ i}\left( {12 + d} \right)*1} + {{r\_ i}\left( {14 + d} \right)*\left( {- 0.17365} \right)} + {{r\_ i}\left( {16 + d} \right)*\left( {- 0.93969} \right)} + {{r\_ i}\left( {18 + d} \right)*\left( {- 1} \right)} + {{r\_ i}\left( {20 + d} \right)*\left( {- 0.93969} \right)} + {{r\_ i}\left( {22 + d} \right)*\left( {- 0.17365} \right)} + {{r\_ i}\left( {24 + d} \right)*1} + {{r\_ i}\left( {26 + d} \right)*\left( {- 0.76604} \right)} + {{r\_ i}\left( {28 + d} \right)*0.76604} + {{r\_ i}\left( {30 + d} \right)*\left( {- 1} \right)} + {{r\_ i}\left( {32 + d} \right)*0.17365} + {{r\_ i}\left( {34 + d} \right)*0.93969}} = {\left\{ {{{r\_ i}\left( {0 + d} \right)} - {{r\_ i}\left( {6 + d} \right)} + {{r\_ i}\left( {12 + d} \right)} - {{r\_ i}\left( {18 + d} \right)} + {{r\_ i}\left( {24 + d} \right)} - {{r\_ i}\left( {30 + d} \right)}} \right\} + {\left\{ {{{r\_ i}\left( {2 + d} \right)} - {{r\_ i}\left( {16 + d} \right)} - {{r\_ i}\left( {20 + d} \right)} + {{r\_ i}\left( {34 + d} \right)}} \right\}*0.93969} + {\left\{ {{{r\_ i}\left( {4 + d} \right)} - {{r\_ i}\left( {14 + d} \right)} - {{r\_ i}\left( {22 + d} \right)} + {{r\_ i}\left( {32 + d} \right)}} \right\}*0.17365} + {\left\{ {{{r\_ i}\left( {8 + d} \right)} - {{r\_ i}\left( {10 + d} \right)} - {{r\_ i}\left( {26 + d} \right)} + {{r\_ i}\left( {28 + d} \right)}} \right\}*0.76604}}}}{{Reven\_ q}{\_ q}} = {{{{r\_ q}\left( {0 + d} \right)*0} + {{r\_ q}\left( {2 + d} \right)*\left( {- 0.34202} \right)} + {{r\_ q}\left( {4 + d} \right)*\left( {- 0.98481} \right)} + {{r\_ q}\left( {6 + d} \right)*0} + {{r\_ q}\left( {8 + d} \right)*0.64279} + {{r\_ q}\left( {10 + d} \right)*\left( {- 0.64279} \right)} + {{r\_ q}\left( {12 + d} \right)*0} + {{r\_ q}\left( {14 + d} \right)*0.98481} + {{r\_ q}\left( {16 + d} \right)*0.34202} + {{r\_ q}\left( {18 + d} \right)*0} + {{r\_ q}\left( {20 + d} \right)*0.34202} + {{r\_ q}\left( {22 + d} \right)*0.98481} + {{r\_ q}\left( {24 + d} \right)*0} + {{r\_ q}\left( {26 + d} \right)*\left( {- 0.64279} \right)} + {{r\_ q}\left( {28 + d} \right)*0.64279} + {{r\_ q}\left( {30 + d} \right)*0} + {{r\_ q}\left( {32 + d} \right)*\left( {- 0.98481} \right)} + {{r\_ q}\left( {34 + d} \right)*\left( {- 0.34202} \right)}} = {{\left\{ {{{- {r\_ q}}\left( {2 + d} \right)} + {{r\_ q}\left( {16 + d} \right)} + {{r\_ q}\left( {20 + d} \right)} - {{r\_ q}\left( {34 + d} \right)}} \right\}*0.34202} + {\left\{ {{{- {r\_ q}}\left( {4 + d} \right)} + {{r\_ q}\left( {14 + d} \right)} + {{r\_ q}\left( {22 + d} \right)} - {{r\_ q}\left( {32 + d} \right)}} \right\}*0.98481} + {\left\{ {{{r\_ q}\left( {8 + d} \right)} - {{r\_ q}\left( {10 + d} \right)} - {{r\_ q}\left( {26 + d} \right)} + {{r\_ q}\left( {28 + d} \right)}} \right\}*0.64279}}}}{{{Ieven\_ i}{\_ q}} = {{{{r\_ i}\left( {0 + d} \right)*0} + {{r\_ i}\left( {2 + d} \right)*\left( {- 0.34202} \right)} + {{r\_ i}\left( {4 + d} \right)*\left( {- 0.98481} \right)} + {{r\_ i}\left( {6 + d} \right)*0} + {{r\_ i}\left( {8 + d} \right)*0.64279} + {{r\_ i}\left( {10 + d} \right)*\left( {- 0.64279} \right)} + {{r\_ i}\left( {12 + d} \right)*0} + {{r\_ i}\left( {14 + d} \right)*0.98481} + {{r\_ i}\left( {16 + d} \right)*0.34202} + {{r\_ i}\left( {18 + d} \right)*0} + {{r\_ i}\left( {20 + d} \right)*0.34202} + {{r\_ i}\left( {22 + d} \right)*0.98481} + {{r\_ i}\left( {24 + d} \right)*0} + {{r\_ i}\left( {26 + d} \right)*\left( {- 0.64279} \right)} + {{r\_ i}\left( {28 + d} \right)*0.64279} + {{r\_ i}\left( {30 + d} \right)*0} + {{r\_ i}\left( {32 + d} \right)*\left( {- 0.98481} \right)} + {{r\_ i}\left( {34 + d} \right)*\left( {- 0.34202} \right)}} = {{\left\{ {{{- {r\_ i}}\left( {2 + d} \right)} + {{r\_ i}\left( {16 + d} \right)} + {{r\_ i}\left( {20 + d} \right)} - {{r\_ i}\left( {34 + d} \right)}} \right\}*0.34202} + {\left\{ {{{- {r\_ i}}\left( {4 + d} \right)} + {{r\_ i}\left( {14 + d} \right)} + {{r\_ i}\left( {22 + d} \right)} - {{r\_ i}\left( {32 + d} \right)}} \right\}*0.98481} + {\left\{ {{{r\_ i}\left( {8 + d} \right)} - {{r\_ i}\left( {10 + d} \right)} - {{r\_ i}\left( {26 + d} \right)} + {{r\_ i}\left( {28 + d} \right)}} \right\}*0.64279}}}}{{{Ieven\_ q}{\_ i}} = {{{{r\_ q}\left( {0 + d} \right)*1} + {{r\_ q}\left( {2 + d} \right)*0.93969} + {{r\_ q}\left( {4 + d} \right)*0.17365} + {{r\_ q}\left( {6 + d} \right)*\left( {- 1} \right)} + {{r\_ q}\left( {8 + d} \right)*0.76604} + {{r\_ q}\left( {10 + d} \right)*\left( {- 0.76604} \right)} + {{r\_ q}\left( {12 + d} \right)*1} + {{r\_ q}\left( {14 + d} \right)*\left( {- 0.17365} \right)} + {{r\_ q}\left( {16 + d} \right)*\left( {- 0.93969} \right)} + {{r\_ q}\left( {18 + d} \right)*\left( {- 1} \right)} + {{r\_ q}\left( {20 + d} \right)*\left( {- 0.93969} \right)} + {{r\_ q}\left( {22 + d} \right)*\left( {- 0.17365} \right)} + {{r\_ q}\left( {24 + d} \right)*1} + {{r\_ q}\left( {26 + d} \right)*\left( {- 0.76604} \right)} + {{r\_ q}\left( {28 + d} \right)*0.76604} + {{r\_ q}\left( {30 + d} \right)*\left( {- 1} \right)} + {{r\_ q}\left( {32 + d} \right)*0.17365} + {{r\_ q}\left( {34 + d} \right)*0.93969}} = {\left\{ {{{r\_ q}\left( {0 + d} \right)} - {{r\_ q}\left( {6 + d} \right)} + {{r\_ q}\left( {12 + d} \right)} - {{r\_ q}\left( {18 + d} \right)} + {{r\_ q}\left( {24 + d} \right)} - {{r\_ q}\left( {30 + d} \right)}} \right\} + {\left\{ {{{r\_ q}\left( {2 + d} \right)} - {{r\_ q}\left( {16 + d} \right)} - {{r\_ q}\left( {20 + d} \right)} + {{r\_ q}\left( {34 + d} \right)}} \right\}*0.93969} + {\left\{ {{{r\_ q}\left( {4 + d} \right)} - {{r\_ q}\left( {14 + d} \right)} - {{r\_ q}\left( {22 + d} \right)} + {{r\_ q}\left( {32 + d} \right)}} \right\}*0.17365} + {\left\{ {{{r\_ q}\left( {8 + d} \right)} - {{r\_ q}\left( {10 + d} \right)} - {{r\_ q}\left( {26 + d} \right)} + {{r\_ q}\left( {28 + d} \right)}} \right\}*0.76604}}}}{{Rodd\_ i}{\_ i}} = {{{{r\_ i}\left( {1 + d} \right)*0.99619} + {{r\_ i}\left( {3 + d} \right)*0.70711} + {{r\_ i}\left( {5 + d} \right)*\left( {- 0.57358} \right)} + {{r\_ i}\left( {7 + d} \right)*\left( {- 0.42262} \right)} + {{r\_ i}\left( {9 + d} \right)*0.70711} + {{r\_ i}\left( {11 + d} \right)*\left( {- 0.42262} \right)} + {{r\_ i}\left( {13 + d} \right)*\left( {- 0.57358} \right)} + {{r\_ i}\left( {15 + d} \right)*0.70711} + {{r\_ i}\left( {17 + d} \right)*0.99619} + {{r\_ i}\left( {19 + d} \right)*0.99619} + {{r\_ i}\left( {21 + d} \right)*0.70711} + {{r\_ i}\left( {23 + d} \right)*\left( {- 0.57358} \right)} + {{r\_ i}\left( {25 + d} \right)*\left( {- 0.42262} \right)} + {{r\_ i}\left( {27 + d} \right)*0.70711} + {{r\_ i}\left( {29 + d} \right)*\left( {- 0.42262} \right)} + {{r\_ i}\left( {31 + d} \right)*\left( {- 0.57358} \right)} + {{r\_ i}\left( {33 + d} \right)*0.70711} + {{r\_ i}\left( {35 + d} \right)*0.99619}} = {{{\left\{ {{{r\_ i}\left( {1 + d} \right)} + {{r\_ i}\left( {17 + d} \right)} + {{r\_ i}\left( {19 + d} \right)} + {{r\_ i}\left( {35 + d} \right)}} \right\}*0.99619} + {\left\{ {{{r\_ i}\left( {3 + d} \right)} + {{r\_ i}\left( {9 + d} \right)} + {{r\_ i}\left( {15 + d} \right)} + {{r\_ i}\left( {21 + d} \right)} + {{r\_ i}\left( {27 + d} \right)} + {{r\_ i}\left( {33 + d} \right)}} \right\}*0.70711} + {\left\{ {{{- {r\_ i}}\left( {5 + d} \right)} - {{r\_ i}\left( {13 + d} \right)} - {{r\_ i}\left( {23 + d} \right)} - {{r\_ i}\left( {31 + d} \right)}} \right\}*0.57358} + {\left\{ {{{- {r\_ i}}\left( {7 + d} \right)} - {{r\_ i}\left( {11 + d} \right)} - {{r\_ i}\left( {25 + d} \right)} - {{r\_ i}\left( {29 + d} \right)}} \right\}*0.42262{Rodd\_ q}{\_ q}}} = {{{{r\_ q}\left( {1 + d} \right)*\left( {- 0.087156} \right)} + {{r\_ q}\left( {3 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ q}\left( {5 + d} \right)*\left( {- 0.81915} \right)} + {{r\_ q}\left( {7 + d} \right)*0.90631} + {{r\_ q}\left( {9 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ q}\left( {11 + d} \right)*0.90631} + {{r\_ q}\left( {13 + d} \right)*\left( {- 0.81915} \right)} + {{r\_ q}\left( {15 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ q}\left( {17 + d} \right)*\left( {- 0.087156} \right)} + {{r\_ q}\left( {19 + d} \right)*\left( {- 0.087156} \right)} + {{r\_ q}\left( {21 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ q}\left( {23 + d} \right)*\left( {- 0.81915} \right)} + {{r\_ q}\left( {25 + d} \right)*0.90631} + {{r\_ q}\left( {27 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ q}\left( {29 + d} \right)*0.90631} + {{r\_ q}\left( {31 + d} \right)*\left( {- 0.81915} \right)} + {{r\_ q}\left( {33 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ q}\left( {35 + d} \right)*\left( {- 0.087156} \right)}} = {{{\left\{ {{{- {r\_ q}}\left( {1 + d} \right)} - {{r\_ q}\left( {17 + d} \right)} - {{r\_ q}\left( {19 + d} \right)} - {{r\_ q}\left( {35 + d} \right)}} \right\}*0.087156} + {\left\{ {{{- {r\_ q}}\left( {3 + d} \right)} - {{r\_ q}\left( {9 + d} \right)} - {{r\_ q}\left( {15 + d} \right)} - {{r\_ q}\left( {21 + d} \right)} - {{r\_ q}\left( {27 + d} \right)} - {{r\_ q}\left( {33 + d} \right)}} \right\}*0.70711} + {\left\{ {{{- {r\_ q}}\left( {5 + d} \right)} - {{r\_ q}\left( {13 + d} \right)} - {{r\_ q}\left( {23 + d} \right)} - {{r\_ q}\left( {31 + d} \right)}} \right\}*0.81915} + {\left\{ {{{r\_ q}\left( {7 + d} \right)} + {{r\_ q}\left( {11 + d} \right)} + {{r\_ q}\left( {25 + d} \right)} + {{r\_ q}\left( {29 + d} \right)}} \right\}*0.90631{Iodd\_ i}{\_ q}}} = {{{{r\_ i}\left( {1 + d} \right)*\left( {- 0.087156} \right)} + {{r\_ i}\left( {3 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ i}\left( {5 + d} \right)*\left( {- 0.81915} \right)} + {{r\_ i}\left( {7 + d} \right)*0.90631} + {{r\_ i}\left( {9 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ i}\left( {11 + d} \right)*0.90631} + {{r\_ i}\left( {13 + d} \right)*\left( {- 0.81915} \right)} + {{r\_ i}\left( {15 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ i}\left( {17 + d} \right)*\left( {- 0.087156} \right)} + {{r\_ i}\left( {19 + d} \right)*\left( {- 0.087156} \right)} + {{r\_ i}\left( {21 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ i}\left( {23 + d} \right)*\left( {- 0.81915} \right)} + {{r\_ i}\left( {25 + d} \right)*0.90631} + {{r\_ i}\left( {27 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ i}\left( {29 + d} \right)*0.90631} + {{r\_ i}\left( {31 + d} \right)*\left( {- 0.81915} \right)} + {{r\_ i}\left( {33 + d} \right)*\left( {- 0.70711} \right)} + {{r\_ i}\left( {35 + d} \right)*\left( {- 0.087156} \right)}} = {{{\left\{ {{{- {r\_ i}}\left( {1 + d} \right)} - {{r\_ i}\left( {17 + d} \right)} - {{r\_ i}\left( {19 + d} \right)} - {{r\_ i}\left( {35 + d} \right)}} \right\}*0.087156} + {\left\{ {{{- {r\_ i}}\left( {3 + d} \right)} - {{r\_ i}\left( {9 + d} \right)} - {{r\_ i}\left( {15 + d} \right)} - {{r\_ i}\left( {21 + d} \right)} - {{r\_ i}\left( {27 + d} \right)} - {{r\_ i}\left( {33 + d} \right)}} \right\}*0.70711} + {\left\{ {{{- {r\_ i}}\left( {5 + d} \right)} - {{r\_ i}\left( {13 + d} \right)} - {{r\_ i}\left( {23 + d} \right)}} \middle| {{- {r\_ i}}\left( {31 + d} \right)} \right\}*0.81915} + {\left\{ {{{r\_ i}\left( {7 + d} \right)} + {{r\_ i}\left( {11 + d} \right)} + {{r\_ i}\left( {25 + d} \right)} + {{r\_ i}\left( {29 + d} \right)}} \right\}*0.90631{Iodd\_ q}{\_ i}}} = {{{{r\_ q}\left( {1 + d} \right)*0.99619} + {{r\_ q}\left( {3 + d} \right)*0.70711} + {{r\_ q}\left( {5 + d} \right)*\left( {- 0.57358} \right)} + {{r\_ q}\left( {7 + d} \right)*\left( {- 0.42262} \right)} + {{r\_ q}\left( {9 + d} \right)*0.70711} + {{r\_ q}\left( {11 + d} \right)*\left( {- 0.42262} \right)} + {{r\_ q}\left( {13 + d} \right)*\left( {- 0.57358} \right)} + {{r\_ q}\left( {15 + d} \right)*0.70711} + {{r\_ q}\left( {17 + d} \right)*0.99619} + {{r\_ q}\left( {19 + d} \right)*0.99619} + {{r\_ q}\left( {21 + d} \right)*0.70711} + {{r\_ q}\left( {23 + d} \right)*\left( {- 0.57358} \right)} + {{r\_ q}\left( {25 + d} \right)*\left( {- 0.42262} \right)} + {{r\_ i}\left( {27 + d} \right)*0.70711} + {{r\_ i}\left( {29 + d} \right)*\left( {- 0.42262} \right)} + {{r\_ q}\left( {31 + d} \right)*\left( {- 0.57358} \right)} + {{r\_ q}\left( {33 + d} \right)*0.70711} + {{r\_ q}\left( {35 + d} \right)*0.99619}} = {{\left\{ {{{r\_ q}\left( {1 + d} \right)} + {{r\_ q}\left( {17 + d} \right)} + {{r\_ q}\left( {19 + d} \right)} + {{r\_ q}\left( {35 + d} \right)}} \right\}*0.99619} + {\left\{ {{{r\_ q}\left( {3 + d} \right)} + {{r\_ q}\left( {9 + d} \right)} + {{r\_ q}\left( {15 + d} \right)} + {{r\_ q}\left( {21 + d} \right)} + {{r\_ q}\left( {27 + d} \right)} + {{r\_ q}\left( {33 + d} \right)}} \right\}*0.70711} + {\left\{ {{{- {r\_ q}}\left( {5 + d} \right)} - {{r\_ q}\left( {13 + d} \right)} - {{r\_ q}\left( {23 + d} \right)} - {{r\_ q}\left( {31 + d} \right)}} \right\}*0.57358} + {\left\{ {{{- {r\_ q}}\left( {7 + d} \right)} - {{r\_ q}\left( {11 + d} \right)} - {{r\_ q}\left( {25 + d} \right)} - {{r\_ q}\left( {29 + d} \right)}} \right\}*0.42262}}}}}}}}}} & \left\lbrack {{Equation}\mspace{14mu} 28} \right\rbrack\end{matrix}$

The process of Equation 28 can be calculated by approximation. In otherwords, the calculation of Equation 28 can be easily conducted byquantization.

For example, it is preferable that the above approximation may beconducted in the form of 0.93969→1, 0.17365→0.125(=⅛),0.76604→0.75(=½+¼), 0.34202→0.375(=¼+⅛), 0.984814→1,0.64279→0.625(=½+⅛), 0.99619→1, 0.70711→0.75(=½+¼), 0.57358→0.625(=½+⅛),0.42262→0.375(=¼+⅛), 0.087156→0.125(=⅛), 0.81915→0.875(=1−⅛), and0.90631→0.875(=1−⅛).

If the concept of Equation 28 is approximated, the following equation 29can be acquired:

$\begin{matrix}{{{{Reven\_ i}{\_ i}} = {{{r\_ i}\left( {0 + d} \right)} - {{r\_ i}\left( {6 + d} \right)} + {{r\_ i}\left( {12 + d} \right)} - {{r\_ i}\left( {18 + d} \right)} + {{r\_ i}\left( {24 + d} \right)} - {{r\_ i}\left( {30 + d} \right)} + {{r\_ i}\left( {2 + d} \right)} - {{r\_ i}\left( {16 + d} \right)} - {{r\_ i}\left( {20 + d} \right)} + {{r\_ i}\left( {34 + d} \right)} + {\left\{ {{{r\_ i}\left( {4 + d} \right)} - {{r\_ i}\left( {14 + d} \right)} - {{r\_ i}\left( {22 + d} \right)} + {{r\_ i}\left( {32 + d} \right)}} \right\}*0.125} + {\left\{ {{{r\_ i}\left( {8 + d} \right)} - {{r\_ i}\left( {10 + d} \right)} - {{r\_ i}\left( {26 + d} \right)} + {{r\_ i}\left( {28 + d} \right)}} \right\}*0.75}}}{{{Reven\_ q}{\_ q}} = {{\left\{ {{{- {r\_ q}}\left( {2 + d} \right)} + {{r\_ q}\left( {16 + d} \right)} + {{r\_ q}\left( {20 + d} \right)} - {{r\_ q}\left( {34 + d} \right)}} \right\}*0.375} + \left\{ {{{- {r\_ q}}\left( {4 + d} \right)} + {{r\_ q}\left( {14 + d} \right)} + {{r\_ q}\left( {22 + d} \right)} - {{r\_ q}\left( {32 + d} \right)}} \right\} + {\left\{ {{{r\_ q}\left( {8 + d} \right)} - {{r\_ q}\left( {10 + d} \right)} - {{r\_ q}\left( {26 + d} \right)} + {{r\_ q}\left( {28 + d} \right)}} \right\}*0.625}}}{{{Ieven\_ i}{\_ q}} = {{\left\{ {{{- {r\_ i}}\left( {2 + d} \right)} + {{r\_ i}\left( {16 + d} \right)} + {{r\_ i}\left( {20 + d} \right)} - {{r\_ i}\left( {34 + d} \right)}} \right\}*0.375} + \left\{ {{{- {r\_ i}}\left( {4 + d} \right)} + {{r\_ i}\left( {14 + d} \right)} + {{r\_ i}\left( {22 + d} \right)} - {{r\_ i}\left( {32 + d} \right)}} \right\} + {\left\{ {{{r\_ i}\left( {8 + d} \right)} - {{r\_ i}\left( {10 + d} \right)} - {{r\_ i}\left( {26 + d} \right)} + {{r\_ i}\left( {28 + d} \right)}} \right\}*0.625}}}{{{Ieven\_ q}{\_ i}} = {{{r\_ q}\left( {0 + d} \right)} - {{r\_ q}\left( {6 + d} \right)} + {{r\_ q}\left( {12 + d} \right)} - {{r\_ q}\left( {18 + d} \right)} + {{r\_ q}\left( {24 + d} \right)} - {{r\_ q}\left( {30 + d} \right)} + {{r\_ q}\left( {2 + d} \right)} - {{r\_ q}\left( {16 + d} \right)} - {{r\_ q}\left( {20 + d} \right)} + {{r\_ q}\left( {34 + d} \right)} + {\left\{ {{{r\_ q}\left( {4 + d} \right)} - {{r\_ q}\left( {14 + d} \right)} - {{r\_ q}\left( {22 + d} \right)} + {{r\_ q}\left( {32 + d} \right)}} \right\}*0.125} + {\left\{ {{{r\_ q}\left( {8 + d} \right)} - {{r\_ q}\left( {10 + d} \right)} - {{r\_ q}\left( {26 + d} \right)} + {{r\_ q}\left( {28 + d} \right)}} \right\}*0.75}}}{{{Rodd\_ i}{\_ i}} = {\left\{ {{{r\_ i}\left( {1 + d} \right)} + {{r\_ i}\left( {17 + d} \right)} + {{r\_ i}\left( {19 + d} \right)} + {{r\_ i}\left( {35 + d} \right)}} \right\} + {\left\{ {{{r\_ i}\left( {3 + d} \right)} + {{r\_ i}\left( {9 + d} \right)} + {{r\_ i}\left( {15 + d} \right)} + {{r\_ i}\left( {21 + d} \right)} + {{r\_ i}\left( {27 + d} \right)} + {{r\_ i}\left( {33 + d} \right)}} \right\}*0.75} + {\left\{ {{{- {r\_ i}}\left( {5 + d} \right)} - {{r\_ i}\left( {13 + d} \right)} - {{r\_ i}\left( {23 + d} \right)} - {{r\_ i}\left( {31 + d} \right)}} \right\}*0.625} + {\left\{ {{{- {r\_ i}}\left( {7 + d} \right)} - {{r\_ i}\left( {11 + d} \right)} - {{r\_ i}\left( {25 + d} \right)} - {{r\_ i}\left( {29 + d} \right)}} \right\}*0.375}}}{{{Rodd\_ q}{\_ q}} = {{\left\{ {{{- {r\_ q}}\left( {1 + d} \right)} - {{r\_ q}\left( {17 + d} \right)} - {{r\_ q}\left( {19 + d} \right)} - {{r\_ q}\left( {35 + d} \right)}} \right\}*0.125} + {\left\{ {{{- {r\_ q}}\left( {3 + d} \right)} - {{r\_ q}\left( {9 + d} \right)} - {{r\_ q}\left( {15 + d} \right)} - {{r\_ q}\left( {21 + d} \right)} - {{r\_ q}\left( {27 + d} \right)} - {{r\_ q}\left( {33 + d} \right)}} \right\}*0.75} + {\left\{ {{{- {r\_ q}}\left( {5 + d} \right)} - {{r\_ q}\left( {13 + d} \right)} - {{r\_ q}\left( {23 + d} \right)} - {{r\_ q}\left( {31 + d} \right)} + {{r\_ q}\left( {7 + d} \right)} + {{r\_ q}\left( {11 + d} \right)} + {{r\_ q}\left( {25 + d} \right)} + {{r\_ q}\left( {29 + d} \right)}} \right\}*0.875}}}{{{Iodd\_ i}{\_ q}} = {{\left\{ {{{- {r\_ i}}\left( {1 + d} \right)} - {{r\_ i}\left( {17 + d} \right)} - {{r\_ i}\left( {19 + d} \right)} - {{r\_ i}\left( {35 + d} \right)}} \right\}*0.125} + {\left\{ {{{- {r\_ i}}\left( {3 + d} \right)} - {{r\_ i}\left( {9 + d} \right)} - {{r\_ i}\left( {15 + d} \right)} - {{r\_ i}\left( {21 + d} \right)} - {{r\_ i}\left( {27 + d} \right)} - {{r\_ i}\left( {33 + d} \right)}} \right\}*0.75} + {\left\{ {{{- {r\_ i}}\left( {5 + d} \right)} - {{r\_ i}\left( {13 + d} \right)} - {{r\_ i}\left( {23 + d} \right)} - {{r\_ i}\left( {31 + d} \right)} + {{r\_ i}\left( {7 + d} \right)} + {{r\_ i}\left( {11 + d} \right)} + {{r\_ i}\left( {25 + d} \right)} + {{r\_ i}\left( {29 + d} \right)}} \right\}*0.875}}}{{{Iodd\_ q}{\_ i}} = {\left\{ {{{r\_ q}\left( {1 + d} \right)} + {{r\_ q}\left( {17 + d} \right)} + {{r\_ q}\left( {19 + d} \right)} + {{r\_ q}\left( {35 + d} \right)}} \right\} + {\left\{ {{{r\_ q}\left( {3 + d} \right)} + {{r\_ q}\left( {9 + d} \right)} + {{r\_ q}\left( {15 + d} \right)} + {{r\_ q}\left( {21 + d} \right)} + {{r\_ q}\left( {27 + d} \right)} + {{r\_ q}\left( {33 + d} \right)}} \right\}*0.75} + {\left\{ {{{- {r\_ q}}\left( {5 + d} \right)} - {{r\_ q}\left( {13 + d} \right)} - {{r\_ q}\left( {23 + d} \right)} - {{r\_ q}\left( {31 + d} \right)}} \right\}*0.625} + {\left\{ {{{- {r\_ q}}\left( {7 + d} \right)} - {{r\_ q}\left( {11 + d} \right)} - {{r\_ q}\left( {25 + d} \right)} - {{r\_ q}\left( {29 + d} \right)}} \right\}*0.375}}}} & \left\lbrack {{Equation}\mspace{14mu} 29} \right\rbrack\end{matrix}$

In this case, it should be noted that the result of Equation 29 isgenerated by a single known sequence (i.e., a sequence corresponding tothe mother sequence index) of the reception end and the Rx signal.Although the reception end must perform the correlation operationassociated with all the four PSCs on the condition that a cell transmitseither one of the four PSCs, the reception end calculates the values ofEquation 29 using only one sequence corresponding to the mother sequenceindex. Also, the cross-correlation value of all the four PSCs can becalculated using the values of Equation 29.

A method for calculating the cross-correlation value associated with allthe four PSCs using the result of Equation 29 is as follows.

$\begin{matrix}\begin{matrix}{{R^{{m\; 0} = 1}(d)} = {{R_{even}^{{m\; 0} = 1}(d)} + {R_{odd}^{{m\; 0} = 1}(d)}}} \\{= {{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + d} \right)}\left( {a^{{m\; 0} = 1}\left( {2l} \right)} \right)^{*}}} +}} \\{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + 1 + d} \right)}\left( {a^{{m\; 0} = 1}\left( {{2l} + 1} \right)} \right)^{*}}}} \\{= {\left( {{Reven}^{0} + {Rodd}^{\mspace{11mu} 0}} \right) + {j\left( {{Ieven}^{0} + {Iodd}^{\; 0}} \right)}}}\end{matrix} & \left\lbrack {{Equation}\mspace{14mu} 30} \right\rbrack \\\begin{matrix}{{R^{{m\; 1} = 17}(d)} = {{R_{even}^{{m\; 1} = 17}(d)} + {R_{odd}^{{m\; 1} = 17}(d)}}} \\{= {{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + d} \right)}\left( {a^{{m\; 1} = 17}\left( {2l} \right)} \right)^{*}}} +}} \\{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + 1 + d} \right)}\left( {a^{{m\; 1} = 17}\left( {{2l} + 1} \right)} \right)^{*}}}} \\{= {{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + d} \right)}\left( \left( {a^{{m\; 0} = 1}\left( {2l} \right)} \right)^{*} \right)^{*}}} +}} \\{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + 1 + d} \right)}\left( {- {j\left( {a^{{m\; 0} = 1}\left( {{2l} + 1} \right)} \right)}^{*}} \right)^{*}}}} \\{= {{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + d} \right)}{a^{{m\; 0} = 1}\left( {2l} \right)}}} +}} \\{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + 1 + d} \right)}\left( {j \cdot {a^{{m\; 0} = 1}\left( {{2l} + 1} \right)}} \right)}}} \\{= {\left( {{Reven}^{1} - {Iodd}^{\mspace{11mu} 1}} \right) + {j\left( {{Ieven}^{1} + {Rodd}^{\; 0}} \right)}}}\end{matrix} & \left\lbrack {{Equation}\mspace{14mu} 31} \right\rbrack \\\begin{matrix}{{R^{{m\; 2} = 19}(d)} = {{R_{even}^{{m\; 2} = 19}(d)} + {R_{odd}^{{m\; 2} = 19}(d)}}} \\{= {{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + d} \right)}\left( {a^{{m\; 2} = 19}\left( {2l} \right)} \right)^{*}}} +}} \\{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + 1 + d} \right)}\left( {a^{{m\; 2} = 19}\left( {{2l} + 1} \right)} \right)^{*}}}} \\{= {{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + d} \right)}\left( {a^{{m\; 0} = 1}\left( {2l} \right)} \right)^{*}}} +}} \\{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + 1 + d} \right)}\left( {{- j} \cdot {a^{{m\; 0} = 1}\left( {{2l} + 1} \right)}} \right)^{*}}}} \\{= {\left( {{Reven}^{0} - {Iodd}^{\mspace{11mu} 0}} \right) + {j\left( {{Ieven}^{0} + {Rodd}^{\; 0}} \right)}}}\end{matrix} & \left\lbrack {{Equation}\mspace{14mu} 32} \right\rbrack \\\begin{matrix}{{R^{{m\; 3} = 35}(d)} = {{R_{even}^{{m\; 3} = 35}(d)} + {R_{odd}^{{m\; 3} = 35}(d)}}} \\{= {{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + d} \right)}\left( {a^{{m\; 3} = 35}\left( {2l} \right)} \right)^{*}}} +}} \\{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + 1 + d} \right)}\left( {a^{{m\; 3} = 35}\left( {{2l} + 1} \right)} \right)^{*}}}} \\{= {{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + d} \right)}\left( \left( {a^{{m\; 0} = 1}\left( {2l} \right)} \right)^{*} \right)^{*}}} +}} \\{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + 1 + d} \right)}\left( {- \left( {a^{{m\; 0} = 1}\left( {{2l} + 1} \right)} \right)^{*}} \right)^{*}}}} \\{= {{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + d} \right)}\left( {a^{{m\; 0} = 1}\left( {2l} \right)} \right)}} +}} \\{{\sum\limits_{l = 0}^{17}{{r\left( {{2l} + 1 + d} \right)}\left( {- {a^{{m\; 0} = 1}\left( {{2l} + 1} \right)}} \right)}}} \\{= {\left( {{Reven}^{1} - {Rodd}^{\mspace{11mu} 1}} \right) + {j\left( {{Ieven}^{1} - {Iodd}^{\; 1}} \right)}}}\end{matrix} & \left\lbrack {{Equation}\mspace{14mu} 33} \right\rbrack\end{matrix}$

Equation 30 is indicative of a cross-correlation value between asequence corresponding to the mother sequence index (m₀) and the Rxsignal. Equation 31 is indicative of a cross-correlation value between asequence corresponding to the remaining sequence index (m₁) and the Rxsignal. Equation 32 is indicative of a cross-correlation value between asequence corresponding to the remaining sequence index (m₂) and the Rxsignal. Equation 33 is indicative of a cross-correlation value between asequence corresponding to the remaining sequence index (m₃) and the Rxsignal.

In brief, if multiple sequences are generated according to the inventivemethods of the above-mentioned embodiments, the present invention cancalculate the cross-correlation value of multiple sequencescorresponding to multiple sequence indexes using both the sequencecorresponding to a single sequence index and the Rx signal.

FIG. 27 is a structural diagram illustrating the reception end accordingto the present invention.

Referring to FIG. 27, the Rx signal of the reception end and the knownsequence of the reception end are applied to the index demapper 1900.The unit 1950 of the reception end of FIG. 27 can calculate “Reven_i_i”,“Revenq_q”, “Ieven_i_q”, “Ieven_q_i”, “Rodd_i_i”, “Rodd_q_q”,“Iodd_i_q”, and “Iodd_q_i” using Equation 29 or 29.

The values “Reven_i_i”, “Revenq_q”, “Ieven_i_q”, “Ieven_q_i”,“Rodd_i_i”, “Rodd_q_q”, “Iodd_i_q”, and “Iodd_q_i” are calculated as“Reven0”, “Ieven0”, “Rodd0”, “Iodd0”, “Reven1”, “Ieven1”, “Rodd1”, and“Iodd1”, respectively, using Equations 24˜27.

For example, “Reven_i_i+Reve_q_q” is calculated as “Reven⁰”,“−Ieven_i_q+Ieven_q_i” is calculated as “Ieven⁰”.

The operations of Equations 24 to 27 are conducted by the unit 1960.

If the addition or subtraction of Equations 30˜33 is applied to the1960-unit's result of Reven0, Ieven0, Rodd0, Iodd0, Reven1, Ieven1,Rodd1, and Iodd1, four correlation values of the individual sequenceindexes (m₀, m_(i), m₂, m₃) can be calculated.

For example, the correlation value of the m₀ value is calculated byEquation 30. In more detail, the sum of Reven⁰ and Rodd⁰ is used as areal part of the correlation value of the m₀ value, and the sum ofIeven⁰ and Iodd⁰ is used as an imaginary part of the m₀ value.

Referring to Equations 24˜33 and FIG. 27, the final result can beacquired by the 1850-unit's result although the “1960” unit does notindependently exist, and it can be recognized that the final result canbe acquired using only the “1960” unit without using the “1950” unit.

The concept of FIG. 27 will also be described according to anotherscheme, and a detailed description thereof will hereinafter bedescribed.

In the case of calculating the cross-correlation value between the Rxsignal and the sequence corresponding to the “m₀” value, provided thatthe real part of the cross-correlation value associated with the even-th“m₀” sequence is set to a first result, the first result may be denotedby Reven⁰ according to Equation 24. In FIG. 27, the reference number“1901” of FIG. 27 indicates the first result.

Provided that the imaginary part of the cross-correlation valueassociated with the even-th “m₀” sequence is set to a second result, thesecond result may be denoted by Ieven⁰ according to Equation 24. In FIG.27, the reference number “1902” of FIG. 27 indicates the second result.

Provided that the real part of the cross-correlation value associatedwith the odd-th “m₀” sequence is set to a third result, the third resultmay be denoted by Rodd⁰ according to Equation 25. In FIG. 27, thereference number “1903” of FIG. 27 indicates the third result.

Provided that the imaginary part of the cross-correlation valueassociated with the odd-th “m₀” sequence is set to a fourth result, thefourth result may be denoted by Iodd⁰ according to Equation 25. In FIG.27, the reference number “1904” of FIG. 27 indicates the fourth result.

Provided that the real part of the cross-correlation value associatedwith a conjugate of the even-th “m₀” sequence is set to a fifth result,the fifth result may be denoted by Reven¹ according to Equation 26. InFIG. 27, the reference number “1905” of FIG. 27 indicates the fifthresult.

Provided that the imaginary part of the cross-correlation valueassociated with a conjugate of the even-th “m₀” sequence is set to asixth result, the sixth result may be denoted by Ieven¹ according toEquation 26. In FIG. 27, the reference number “1906” of FIG. 27indicates the sixth result.

Provided that the real part of the cross-correlation value associatedwith a conjugate of the odd-th “m₀” sequence is set to a seventh result,the seventh result may be denoted by Rodd¹ according to Equation 27. InFIG. 27, the reference number “1907” of FIG. 27 indicates the seventhresult.

Provided that the imaginary part of the cross-correlation valueassociated with a conjugate of the odd-th “m₀” sequence is set to aneighth result, the eighth result may be denoted by Iodd¹ according toEquation 27. In FIG. 27, the reference number “1908” of FIG. 27indicates the eighth result.

According to the above-mentioned method, the first to eighth results aredecided. If two results of the aforementioned eight results are added orsubtracted from each other, the calculation value of the “1970” unit isacquired.

For example, the real part of the correlation value of the “m₀” sequenceis equal to the sum of the “1901” unit and the “1903” unit. Theimaginary part of the correlation value of the “m₀” sequence is equal tothe sum of the “1906” unit and the “1906” unit.

In brief, the reception end calculates the above-mentioned first toeighth results, and may perform the addition or subtraction between twodifferent results from among the first to eighth results, so that it cancalculate the cross-correlation value of the “m₀˜m₃” sequences.

FIG. 27 shows a specific case in which the sequence length is denoted byan even number. It is obvious to those skilled in the art that theabove-mentioned concept may also be applied to not only the even numberbut also the odd number.

Next, a receiver of the odd-length sequence will hereinafter bedescribed with reference to FIG. 18 and the following equations.

Firstly, if the sequence length is 35, two sequence indexes can beselected.

For example, the length of the mother sequence index may be set to “1”and the length of the remaining sequence index may be set to “34”.

In this case, the expression corresponding to Equation 23 is representedby the following equation 34:

$\begin{matrix}{{{a^{{m\; 0} = 1}(k)} = {\exp \left( {{- j}\; {\pi \cdot 1 \cdot \frac{k\left( {k + 1} \right)}{35}}} \right)}}\begin{matrix}{{a^{{m\; 1} = 34}(k)} = {\exp \left( {{- j}\; {\pi \cdot 34 \cdot \frac{k\left( {k + 1} \right)}{35}}} \right)}} \\{= {\exp \left( {{- j}\; {\pi \cdot \left( {35 - 1} \right) \cdot \frac{k\left( {k + 1} \right)}{35}}} \right)}} \\{= {\exp \left( {{- j}\; \left( {{\pi \; {k\left( {k + 1} \right)}} + {\pi \cdot \frac{k\left( {k + 1} \right)}{35}}} \right)} \right)}} \\{= \left( {a^{{m\; 0} = 1}(k)} \right)^{*}}\end{matrix}} & \left\lbrack {{Equation}\mspace{14mu} 34} \right\rbrack\end{matrix}$

In this case, the cross-correlation value can be represented by thefollowing equation 35:

$\begin{matrix}{\begin{matrix}{{R^{{m\; 0} = 1}(d)} = {\frac{1}{N}{\sum\limits_{n = 0}^{N - 1}{{r\left( {n + d} \right)}\left( {a^{{m\; 0} = 1}(n)} \right)^{*}}}}} \\{= {\frac{1}{N}{\sum\limits_{n = 0}^{N - 1}\left( \left( {{{r_{I}\left( {n + d} \right)}{a_{I}^{{m\; 0} = 1}(n)}} +} \right. \right.}}} \\{\left. {{r_{Q}\left( {n + d} \right)}{a_{Q}^{{m\; 0} = 1}(n)}} \right) +} \\{{j\left( {{{r_{Q}\left( {n + d} \right)}{a_{I}^{{m\; 0} = 1}(n)}} -} \right.}} \\\left. \left. {{r_{I}\left( {n + d} \right)}{a_{Q}^{{m\; 0} = 1}(n)}} \right) \right)\end{matrix}\begin{matrix}{{R^{{m\; 2} = 34}(d)} = {\frac{1}{N}{\sum\limits_{n = 0}^{N - 1}{{r\left( {n + d} \right)}\left( {a^{{m\; 0} = 1}(n)}^{*} \right)^{*}}}}} \\{= {\frac{1}{N}{\sum\limits_{n = 0}^{N - 1}\left( \left( {{{r_{I}\left( {n + d} \right)}{a_{I}^{{m\; 0} = 1}(n)}} -} \right. \right.}}} \\{\left. {{r_{Q}\left( {n + d} \right)}{a_{Q}^{{m\; 0} = 1}(n)}} \right) +} \\{{j\left( {{{r_{Q}\left( {n + d} \right)}{a_{I}^{{m\; 0} = 1}(n)}} +} \right.}} \\\left. \left. {{r_{I}\left( {n + d} \right)}{a_{Q}^{{m\; 0} = 1}(n)}} \right) \right)\end{matrix}} & \left\lbrack {{Equation}\mspace{14mu} 35} \right\rbrack\end{matrix}$

In order to briefly express the result of Equation 35, the variablesshown in the following equation 36 are defined as follows:

$\begin{matrix}{{R_{II} = {\frac{1}{N}{\sum\limits_{n = 0}^{N - 1}\left( {{r_{I}\left( {n + d} \right)}{a_{I}^{{m\; 0} = 1}(n)}} \right)}}}{R_{QQ} = {\frac{1}{N}{\sum\limits_{n = 0}^{N - 1}\left( {{r_{Q}\left( {n + d} \right)}{a_{Q}^{{m\; 0} = 1}(n)}} \right)}}}{I_{QI} = {\frac{1}{N}{\sum\limits_{n = 0}^{N - 1}\left( {{r_{Q}\left( {n + d} \right)}{a_{I}^{{m\; 0} = 1}(n)}} \right)}}}{I_{IQ} = {\frac{1}{N}{\sum\limits_{n = 0}^{N - 1}\left( {{r_{I}\left( {n + d} \right)}{a_{Q}^{{m\; 0} = 1}(n)}} \right)}}}} & \left\lbrack {{Equation}\mspace{14mu} 36} \right\rbrack\end{matrix}$

Based on the above Equation 36, the result of Equation 35 can berepresented by the following equation 37:

R ^(m0=1)(d)=(R _(II) +R _(QQ))+j(I _(QI) −I _(IQ))

R ^(m2=34)(d)=(R _(II) −R _(QQ))+j(I _(QI) +I _(IQ))  [Equation 37]

The exemplary reception end for calculating Equation 37 is shown in FIG.28.

In FIG. 28, four variables are calculated by Equation 36, so that thecorrelation value of the odd-length sequence is calculated at one time.Therefore, in the case of using the above-mentioned structure, thepresent invention can properly process the reception case of thesequence with the length 63.

As described above, the reception end associated with sequences havingvarious lengths can be designed.

<Case 2>

This example shows a method for calculating the cross-correlation valueof the selected sequences, which have the length of 32 and the valuesm_(o)=1, m₁=15, m₂=17, m₃=32.

This embodiment of Case 2 will show detailed equations because the Case1 has already described the detailed methods. And, it can be recognizedthat which one of equations shown in FIG. 1 is considered to be equal toeach equation of Case 2.

As well known to those skilled in the art, the Case 2 and a method forreceiving various sequence indexes can be conducted on the basis of theexplanation of Case 1.

$\begin{matrix}{{R^{m}(d)} = {\frac{1}{LN}{\sum\limits_{n = 0}^{{LN} - 1}\; {{r\left( {n + d} \right)}\left( {a^{m}(n)} \right)^{*}}}}} & \left\lbrack {{Equation}\mspace{14mu} 38} \right\rbrack\end{matrix}$

Equation 38 is equal to Equation 22.

$\begin{matrix}{\mspace{79mu} {{{a^{{m\; 0} = 1}(k)} = {\exp \left( {{- j}\; {\pi \cdot 1 \cdot \frac{k^{2}}{32}}} \right)}}{{a^{{m\; 1} = 15}(k)} = {{\exp \left( {{- j}\; {\pi \cdot 15 \cdot \frac{k^{2}}{32}}} \right)} = {{\exp \left( {{- j}\; {\pi \cdot \left( {16 - 1} \right) \cdot \frac{k^{2}}{32}}} \right)} = {{\exp \left( {- {j\left( {{\frac{\pi}{2}k^{2}} - {\frac{\pi}{32}k^{2}}} \right)}} \right)} = \left\{ {{\begin{matrix}{\left( {a_{even}^{{m\; 0} = 1}(k)} \right)^{*},} & {{when}\mspace{14mu} k\mspace{14mu} {is}\mspace{14mu} {even}} \\{{{- j} \cdot \left( {a_{odd}^{{m\; 0} = 1}(k)} \right)^{*}},} & {otherwise}\end{matrix}{a^{{m\; 2} = 17}(k)}} = {{\exp \left( {{- j}\; {\pi \cdot 17 \cdot \frac{k^{2}}{32}}} \right)} = {{\exp \left( {{- j}\; {\pi \cdot \left( {16 + 1} \right) \cdot \frac{k^{2}}{32}}} \right)} = {{\exp \left( {- {j\left( {{\frac{\pi}{2}k^{2}} + {\frac{\pi}{32}k^{2}}} \right)}} \right)} = \left\{ {{\begin{matrix}{{a_{even}^{{m\; 0} = 1}(k)},} & {{when}\mspace{14mu} k\mspace{14mu} {is}\mspace{14mu} {even}} \\{{{- j} \cdot {a_{odd}^{{m\; 0} = 1}(k)}},} & {otherwise}\end{matrix}{a^{{m\; 3} = 31}(k)}} = {{\exp \left( {{- j}\; {\pi \cdot 31 \cdot \frac{k^{2}}{32}}} \right)} = {{\exp \left( {{- j}\; {\pi \cdot \left( {32 - 1} \right) \cdot \frac{k^{2}}{32}}} \right)} = {{\exp \left( {- {j\left( {{\pi \; k^{2}} - {\frac{\pi}{32}k^{2}}} \right)}} \right)} = \left\{ \begin{matrix}{\left( {a_{even}^{{m\; 0} = 1}(k)} \right)^{*},} & {{when}\mspace{14mu} k\mspace{14mu} {is}\mspace{14mu} {even}} \\{{- \left( {a_{odd}^{{m\; 0} = 1}(k)} \right)^{*}},} & {otherwise}\end{matrix} \right.}}}} \right.}}}} \right.}}}}}} & \left\lbrack {{Equation}\mspace{14mu} 39} \right\rbrack\end{matrix}$

Equation 39 is equal to Equation 23.

$\begin{matrix}{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + d} \right)}\left( {a^{{m\; 0} = 1}\left( {2\; l} \right)} \right)^{*}}} = {{\left( {{{Reven\_ i}{\_ i}} + {{Reven\_ q}{\_ q}}} \right) + {j\left( {{{- {Ieven\_ i}}{\_ q}} + {{Ieven\_ q}{\_ i}}} \right)}} = {{Reven}^{0} + {jIeven}^{0}}}} & \left\lbrack {{Equation}\mspace{14mu} 40} \right\rbrack\end{matrix}$

Equation 40 corresponds to Equation 24.

$\begin{matrix}{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + 1 + d} \right)}\left( {a^{{m\; 0} = 1}\left( {2\; l} \right)} \right)^{*}}} = {{\left( {{{Rodd\_ i}{\_ i}} + {{Rodd\_ q}{\_ q}}} \right) + {j\left( {{{- {Iodd\_ i}}{\_ q}} + {{Iodd\_ q}{\_ i}}} \right)}} = {{Rodd}^{0} + {jIodd}^{0}}}} & \left\lbrack {{Equation}\mspace{14mu} 41} \right\rbrack\end{matrix}$

Equation 40 corresponds to Equation 25.

$\begin{matrix}{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + d} \right)}{a^{{m\; 0} = 1}\left( {2\; l} \right)}}} = {{\left( {{{Reven\_ i}{\_ i}} - {{Reven\_ q}{\_ q}}} \right) + {j\left( {{{Ieven\_ i}{\_ q}} + {{Ieven\_ q}{\_ i}}} \right)}} = {{Reven}^{1} + {jIeven}^{1}}}} & \left\lbrack {{Equation}\mspace{14mu} 42} \right\rbrack\end{matrix}$

Equation 42 corresponds to Equation 26.

$\begin{matrix}{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + 1 + d} \right)}{a^{{m\; 0} = 1}\left( {{2\; l} + 1} \right)}}} = {{\left( {{{Rodd\_ i}{\_ i}} - {{Rodd\_ q}{\_ q}}} \right) + {j\left( {{{Iodd\_ i}{\_ q}} + {{Iodd\_ q}{\_ i}}} \right)}} = {{Rodd}^{1} + {jIodd}^{1}}}} & \left\lbrack {{Equation}\mspace{14mu} 43} \right\rbrack\end{matrix}$

Equation 43 corresponds to Equation 27.

                                       [Equation  44]Reven_i_i = r_i(0 + d) * 1 + r_i(2 + d) * 0.92388 + r_i(4 + d) * 0 + r_i(6 + d) * (−0.92388) + r_i(8 + d) * 1 + r_i(10 + d) * (−0.92388) + r_i(12 + d) * 0 + r_i(14 + d) * 0.92388 + r_i(16 + d) * 1 + r_i(18 + d) * 0.92388 + r_i(20 + d) * 0 + r_i(22 + d) * (−0.92388) + r_i(24 + d) * 1 + r_i(26 + d) * (−0.92388) + r_i(28 + d) * 0 + r_i(30 + d) * 0.92388 = {r_i(0 + d) + r_i(8 + d) + r_i(16 + d) + r_i(24 + d)} + {r_i(2 + d) − r_i(6 + d) − r_i(10 + d) + r_i(14 + d) + r_i(18 + d) − r_i(22 + d) − r_i(26 + d) + r_i(30 + d)} * 0.92388

Reven_q_q = r_q(0 + d) * 0 + r_q(2 + d) * (−0.38268) + r_q(4 + d) * (−1) + r_q(6 + d) * 0.38268 + r_q(8 + d) * 0 + r_q(10 + d) * 0.38268 + r_q(12 + d) * (−1) + r_q(14 + d) * (−0.38268) + r_q(16 + d) * 0 + r_q(18 + d) * (−0.38268) + r_q(20 + d) * (−1) + r_q(22 + d) * 0.38268 + r_q(24 + d) * 0 + r_q(26 + d) * 0.38268 + r_q(28 + d) * (−1) + r_q(30 + d) * (−0.38268) = {−r_q(2 + d) + r_q(6 + d) + r_q(10 + d) − r_q(14 + d) − r_q(18 + d) + r_q(22 + d) + r_q(26 + d) − r_q(30 + d)} * 0.38268 + {−r_q(4 + d) − r_q(12 + d) − r_q(20 + d) − r_q(28 + d)}

Ieven_i_q = r_i(0 + d) * 0 + r_i(2 + d) * (−0.38268) + r_i(4 + d) * (−1) + r_i(6 + d) * 0.38268 + r_i(8 + d) * 0 + r_i(10 + d) * 0.38268 + r_i(12 + d) * (−1) + r_i(14 + d) * (−0.38268) + r_i(16 + d) * 0 + r_i(18 + d) * (−0.38268) + r_i(20 + d) * (−1) + r_i(22 + d) * 0.38268 + r_i(24 + d) * 0 + r_i(26 + d) * 0.38268 + r_i(28 + d) * (−1) + r_i(30 + d) * (−0.38268) = {−r_i(2 + d) + r_i(6 + d) + r_i(10 + d) − r_i(14 + d) − r_i(18 + d) + r_i(22 + d) + r_i(26 + d) − r_i(30 + d)} * 0.38268 + {−r_i(4 + d) − r_i(12 + d) − r_i(20 + d) − r_i(28 + d)}

Ieven_q_i = r_q(0 + d) * 1 + r_q(2 + d) * 0.92388 + r_q(4 + d) * 0 + r_q(6 + d) * (−0.92388) + r_q(8 + d) * 1 + r_q(10 + d) * (−0.92388) + r_q(12 + d) * 0 + r_q(14 + d) * 0.92388 + r_q(16 + d) * 1 + r_q(18 + d) * 0.92388 + r_q(20 + d) * 0 + r_q(22 + d) * (−0.92388) + r_q(24 + d) * 1 + r_q(26 + d) * (−0.92388) + r_q(28 + d) * 0 + r_q(30 + d) * 0.92388 = {r_q(0 + d) + r_q(8 + d) + r_q(16 + d) + r_q(24 + d)} + {r_q(2 + d) − r_q(6 + d) − r_q(10 + d) + r_q(14 + d) + r_q(18 + d) − r_q(22 + d) − r_q(26 + d) + r_q(30 + d)} * 0.92388

Rodd_i_i = r_i(1 + d) * (−0.098017) + r_i(3 + d) * (−0.77301) + r_i(5 + d) * (−0.63439) + r_i(7 + d) * 0.99518 + r_i(9 + d) * (−0.99518) + r_i(11 + d) * 0.63439 + r_i(13 + d) * 0.77301 + r_i(15 + d) * 0.098017 + r_i(17 + d) * 0.098017 + r_i(19 + d) * 0.77301 + r_i(21 + d) * 0.63439 + r_i(23 + d) * (−0.99518) + r_i(25 + d) * 0.99518 + r_i(27 + d) * (−0.63439) + r_i(29 + d) * (−0.77301) + r_i(31 + d) * (−0.098017) = {−r_i(1 + d) + r_i(15 + d) + r_i(17 + d) − r_i(31 + d)} * 0.098017 + {−r_i(3 + d) + r_i(13 + d) + r_i(19 + d) − r_i(29 + d)} * 0.77301 + {−r_i(5 + d) + r_i(11 + d) + r_i(21 + d) − r_i(27 + d)} * 0.63439 + {r_i(7 + d) − r_i(9 + d) − r_i(23 + d) + r_i(25 + d)} * 0.99518

Rodd_q_q = r_q(1 + d) * (−0.098017) + r_q(3 + d) * (−0.77301) + r_q(5 + d) * (−0.63439) + r_q(7 + d) * 0.99518 + r_q(9 + d) * (−0.99518) + r_q(11 + d) * 0.63439 + r_q(13 + d) * 0.77301 + r_q(15 + d) * 0.098017 + r_q(17 + d) * 0.098017 + r_q(19 + d) * 0.77301 + r_q(21 + d) * 0.63439 + r_q(23 + d) * (−0.99518) + r_q(25 + d) * 0.99518 + r_q(27 + d) * (−0.63439) + r_q(29 + d) * (−0.77301) + r_q(31 + d) * (−0.098017) = {−r_q(1 + d) + r_q(15 + d) + r_q(17 + d) − r_q(31 + d)} * 0.098017 + {−r_q(3 + d) + r_q(13 + d) + r_q(19 + d) − r_q(29 + d)} * 0.77301 + {−r_q(5 + d) + r_q(11 + d) + r_q(21 + d) − r_q(27 + d)} * 0.63439 + {r_q(7 + d) − r_q(9 + d) − r_q(23 + d) + r_q(25 + d)} * 0.99518

Iodd_i_q = r_i(1 + d) * (−0.098017) + r_i(3 + d) * (−0.77301) + r_i(5 + d) * (−0.63439) + r_i(7 + d) * 0.99518 + r_i(9 + d) * (−0.99518) + r_i(11 + d) * 0.63439 + r_i(13 + d) * 0.77301 + r_i(15 + d) * 0.098017 + r_i(17 + d) * 0.098017 + r_i(19 + d) * 0.77301 + r_i(21 + d) * 0.63439 + r_i(23 + d) * (−0.99518) + r_i(25 + d) * 0.99518 + r_i(27 + d) * (−0.63439) + r_i(29 + d) * (−0.77301) + r_i(31 + d) * (−0.098017) = {−r_i(1 + d) + r_i(15 + d) + r_i(17 + d) − r_i(31 + d)} * 0.098017 + {−r_i(3 + d) + r_i(13 + d) + r_i(19 + d) − r_i(29 + d)} * 0.77301 + {−r_i(5 + d) + r_i(11 + d) + r_i(21 + d) − r_i(27 + d)} * 0.63439 + {r_i(7 + d) − r_i(9 + d) − r_i(23 + d) + r_i(25 + d)} * 0.99518

Iodd_q_i = r_q(1 + d) * (−0.098017) + r_q(3 + d) * (−0.77301) + r_q(5 + d) * (−0.63439) + r_q(7 + d) * 0.99518 + r_q(9 + d) * (−0.99518) + r_q(11 + d) * 0.63439 + r_q(13 + d) * 0.77301 + r_q(15 + d) * 0.098017 + r_q(17 + d) * 0.098017 + r_q(19 + d) * 0.77301 + r_q(21 + d) * 0.63439 + r_q(23 + d) * (−0.99518) + r_q(25 + d) * 0.99518 + r_q(27 + d) * (−0.63439) + r_q(29 + d) * (−0.77301) + r_q(31 + d) * (−0.098017) = {−r_q(1 + d) + r_q(15 + d) + r_q(17 + d) − r_q(31 + d)} * 0.098017 + {−r_q(3 + d) + r_q(13 + d) + r_q(19 + d) − r_q(29 + d)} * 0.77301 + {−r_q(5 + d) + r_q(11 + d) + r_q(21 + d) − r_q(27 + d)} * 0.63439 + {r_q(7 + d) − r_q(9 + d) − r_q(23 + d) + r_q(25 + d)} * 0.99518

Equation 44 corresponds to Equation 28.

                                       [Equation  45]Reven_i_i = {r_i(0 + d) + r_i(8 + d) + r_i(16 + d) + r_i(24 + d)} + {r_i(2 + d) − r_i(6 + d) − r_i(10 + d) + r_i(14 + d) + r_i(18 + d) − r_i(22 + d) − r_i(26 + d) + r_i(30 + d)} * 0.875Reven_q_q = {−r_q(2 + d) + r_q(6 + d) + r_q(10 + d) − r_q(14 + d) − r_q(18 + d) + r_q(22 + d) + r_q(26 + d) − r_q(30 + d)} * 0.375 + {−r_q(4 + d) − r_q(12 + d) − r_q(20 + d) − r_q(28 + d)}Ieven_i_q = {−r_i(2 + d) + r_i(6 + d) + r_i(10 + d) − r_i(14 + d) − r_i(18 + d) + r_i(22 + d) + r_i(26 + d) − r_i(30 + d)} * 0.375 + {−r_i(4 + d) − r_i(12 + d) − r_i(20 + d) − r_i(28 + d)}Ieven_q_i = {r_q(0 + d) + r_q(8 + d) + r_q(16 + d) + r_q(24 + d)} + {r_q(2 + d) − r_q(6 + d) − r_q(10 + d) + r_q(14 + d) + r_q(18 + d) − r_q(22 + d) − r_q(26 + d) + r_q(30 + d)} * 0.875Rodd_i_i = {−r_i(1 + d) + r_i(15 + d) + r_i(17 + d) − r_i(31 + d)} * 0.125 + {−r_i(3 + d) + r_i(13 + d) + r_i(19 + d) − r_i(29 + d)} * 0.75 + {−r_i(5 + d) + r_i(11 + d) + r_i(21 + d) − r_i(27 + d)} * 0.625 + {r_i(7 + d) − r_i(9 + d) − r_i(23 + d) + r_i(25 + d)}Rodd_q_q = {−r_q(1 + d) + r_q(15 + d) + r_q(17 + d) − r_q(31 + d)} * 0.125 + {−r_q(3 + d) + r_q(13 + d) + r_q(19 + d) − r_q(29 + d)} * 0.75 + {−r_q(5 + d) + r_q(11 + d) + r_q(21 + d) − r_q(27 + d)} * 0.625 + {r_q(7 + d) − r_q(9 + d) − r_q(23 + d) + r_q(25 + d)}Iodd_i_q = {−r_i(1 + d) + r_i(15 + d) + r_i(17 + d) − r_i(31 + d)} * 0.125 + {−r_i(3 + d) + r_i(13 + d) + (19 + d) − r_i(29 + d)} * 0.75 + {−r_i(5 + d) + r_i(11 + d) + r_i(21 + d) − r_i(27 + d)} * 0.625 + {r_i(7 + d) − r_i(9 + d) − r_i(23 + d) + r_i(25 + d)}Iodd_q_i = {−r_q(1 + d) + r_q(15 + d) + r_q(17 + d) − r_q(31 + d)} * 0.125 + {−r_q(3 + d) + r_q(13 + d) + r_q(19 + d) − r_q(29 + d)} * 0.75 + {−r_q(5 + d) + r_q(11 + d) + r_q(21 + d) − r_q(27 + d)} * 0.625 + {r_q(7 + d) − r_q(9 + d) − r_q(23 + d) + r_q(25 + d)}

Equation 45 corresponds to Equation 29.

$\begin{matrix}{{R^{{m\; 0} = 1}(d)} = {{{R_{even}^{{m\; 0} = 1}(d)} + {R_{odd}^{{m\; 0} = 1}(d)}} = {{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + d} \right)}\left( {a^{{m\; 0} = 1}\left( {2\; l} \right)} \right)^{*}}} + {\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + 1 + d} \right)}\left( {a^{{m\; 0} = 1}\left( {{2\; l} + 1} \right)} \right)^{*}}}} = {\left( {{Reven}^{0} + {Rodd}^{0}} \right) + {j\left( {{Ieven}^{0} + {Iodd}^{0}} \right)}}}}} & \left\lbrack {{Equation}\mspace{14mu} 46} \right\rbrack\end{matrix}$

Equation 46 corresponds to Equation 30.

$\begin{matrix}{{R^{{m\; 1} = 15}(d)} = {{{R_{even}^{{m\; 1} = 15}(d)} + {R_{odd}^{{m\; 1} = 15}(d)}} = {{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + d} \right)}\left( {a^{{m\; 1} = 15}\left( {2\; l} \right)} \right)^{*}}} + {\sum\limits_{l = 0}^{15}\; {r\left( {{2\; l} + 1 + d} \right)\left( {a^{{m\; 1} = 15}\left( {{2\; l} + 1} \right)} \right)^{*}}}} = {{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + d} \right)}\left( \left( {a^{{m\; 0} = 1}\left( {2\; l} \right)} \right)^{*} \right)^{*}}} + {\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + 1 + d} \right)}\left( {- {j\left( {a^{{m\; 1} = 15}\left( {{2\; l} + 1} \right)} \right)}^{*}} \right)^{*}}}} = {{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + d} \right)}\left( {a^{{m\; 0} = 1}\left( {2\; l} \right)} \right)}} + {\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + 1 + d} \right)}\left( {j \cdot {a^{{m\; 0} = 1}\left( {{2\; l} + 1} \right)}} \right)}}} = {\left( {{Reven}^{1} - {Iodd}^{1}} \right) + {j\left( {{Ieven}^{1} + {Rodd}^{1}} \right)}}}}}}} & \left\lbrack {{Equation}\mspace{20mu} 47} \right\rbrack\end{matrix}$

Equation 47 corresponds to Equation 31.

$\begin{matrix}{{R^{{m\; 2} = 17}(d)} = {{{R_{even}^{{m\; 2} = 17}(d)} + {R_{odd}^{{m\; 2} = 17}(d)}} = {{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + d} \right)}\left( {a^{{m\; 2} = 17}\left( {2\; l} \right)} \right)^{*}}} + {\sum\limits_{l = 0}^{15}\; {r\left( {{2\; l} + 1 + d} \right)\left( {a^{{m\; 2} = 17}\left( {{2\; l} + 1} \right)} \right)^{*}}}} = {{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + d} \right)}\left( {a^{{m\; 0} = 1}\left( {2\; l} \right)} \right)^{*}}} + {\sum\limits_{l = 0}^{15}\; {r\left( {{2\; l} + 1 + d} \right)\left( {{- j} \cdot {a^{{m\; 0} = 1}\left( {{2\; l} + 1} \right)}} \right)^{*}}}} = {\left( {{Reven}^{0} - {Iodd}^{0}} \right) + {j\left( {{Ieven}^{0} + {Rodd}^{0}} \right)}}}}}} & \left\lbrack {{Equation}\mspace{20mu} 48} \right\rbrack\end{matrix}$

Equation 48 corresponds to Equation 32.

$\begin{matrix}{{R^{{m\; 3} = 31}(d)} = {{{R_{even}^{{m\; 3} = 31}(d)} + {R_{odd}^{{m\; 3} = 31}(d)}} = {{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + d} \right)}\left( {a^{{m\; 3} = 31}\left( {2\; l} \right)} \right)^{*}}} + {\sum\limits_{l = 0}^{15}\; {r\left( {{2\; l} + 1 + d} \right)\left( {a^{{m\; 3} = 31}\left( {{2\; l} + 1} \right)} \right)^{*}}}} = {{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + d} \right)}\left( \left( {a^{{m\; 0} = 1}\left( {2\; l} \right)} \right)^{*} \right)^{*}}} + {\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + 1 + d} \right)}\left( {- \left( {a^{{m\; 0} = 1}\left( {{2\; l} + 1} \right)} \right)^{*}} \right)^{*}}}} = {{{\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + d} \right)}\left( {a^{{m\; 0} = 1}\left( {2\; l} \right)} \right)}} + {\sum\limits_{l = 0}^{15}\; {{r\left( {{2\; l} + 1 + d} \right)}\left( {- {a^{{m\; 0} = 1}\left( {{2\; l} + 1} \right)}} \right)}}} = {\left( {{Reven}^{1} - {Rodd}^{1}} \right) + {j\left( {{Ieven}^{1} - {Iodd}^{1}} \right)}}}}}}} & \left\lbrack {{Equation}\mspace{14mu} 49} \right\rbrack\end{matrix}$

Equation 49 corresponds to Equation 33.

This embodiment can greatly reduce the number of calculations, and adetailed description thereof will hereinafter be described.

In order to calculate the d-th correlation value associated with the PSCsequence, which has the length L=36 and is classified into four types,the conventional method requires 575 real-value multiplications and 568real-value additions on the assumption that the calculations caused bythe sign converter are ignored.

However, the present invention requires 28 real-value multiplicationsand 140 real-value additions. In the case of quantization, the presentinvention requires no real-value multiplication, 156 real-valueadditions, and the shift operation of 54 bits.

The sign converter and the bit-shifting operation are not contained inthe number of calculations when the hardware is implemented, so that thenumber of calculations of each technique is shown in the following Table20. The present invention can calculate the cross-correlation value offour PSC sequences using only 156 real-value additions.

TABLE 26 The number of calculations # of real multiplications # of realadditions Conventional method 576 568 This embodiment 28 140 Embodiment0 156 approximated by quantization

And, if the length (L) is set to 32, there arises a difference inperformance between the conventional art and the present invention, asrepresented by the following Table 27:

TABLE 27 The number of calculations # of real multiplications # of realadditions Conventional method 512 504 This embodiment 20 120 Embodiment0 132 approximated by quantization

It should be noted that most terminology disclosed in the presentinvention is defined in consideration of functions of the presentinvention, and can be differently determined according to intention ofthose skilled in the art or usual practices. Therefore, it is preferablethat the above-mentioned terminology be understood on the basis of allcontents disclosed in the present invention.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

The sequence generated by the present invention maintains correlationcharacteristics of at least a predetermined level in a time domain, andhas low PAPR characteristics. Moreover, by using the sequence generatedby the one embodiment of the present invention, the receiving end caneasily detect the sequence by one correlation operation.

The present invention may configure a superior-performance channel onthe condition that the sequence is applied to a communication standardsuch as the LTE system.

As apparent from the above description, the sequence generated by thepresent invention maintains the correlation characteristics of more thana predetermined level, and has low PAPR characteristics.

If the sequence proposed by the present invention is applied to thecommunication standard such as the LTE system, it can configure achannel having a superior performance.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

What is claimed is:
 1. A system, comprising: a receiver component thatreceives a radio signal; and a processing component that detects asequence in the radio signal, wherein the sequence is based on aZadoff-Chu sequence having an index in an index set, wherein a sum of afirst index and a second index in the index set corresponds to a lengthof the Zadoff-Chu sequence.
 2. The system of claim 1, wherein the lengthof the Zadoff-Chu sequence is odd.
 3. The system of claim 1, wherein thesequence is based on the following equation:$\exp \left( {{- i}\frac{M\; \pi \; {n\left( {n + 1} \right)}}{N}} \right)$wherein “N” is the length of the Zadoff-Chu sequence, “M” is a rootindex of the Zadoff-Chu sequence, and “n” is an index of each ofconstituent components of the sequence.
 4. The system of claim 3,wherein “N” is 63, the first index is 34, and the second index is
 29. 5.The system of claim 1, wherein the radio signal is a P-SCH (Primary-SCH)signal.
 6. The system of claim 1, wherein the receiver component canperform synchronization based on sequence detection performed on theradio signal.
 7. The system of claim 1, wherein the radio signal isgenerated in a frequency domain.
 8. The system of claim 1, wherein theprocessing component employs an index demapper.
 9. A system, comprising:a mapping component that maps a sequence to a resource element, whereinthe sequence is based on a Zadoff-Chu sequence having an index in anindex set, wherein a sum of a first index and a second index in theindex set corresponds to a length of the Zadoff-Chu sequence; aconversion component that converts the sequence into a time-domaintransmission signal via an Inverse Fast Fourier Transform; and atransmitter component that transmits the time-domain transmissionsignal.
 10. The system of claim 9, wherein the length of the Zadoff-Chusequence is odd.
 11. The system of claim 9, wherein the sequence isbased on the following equation:$\exp \left( {{- i}\frac{M\; \pi \; {n\left( {n + 1} \right)}}{N}} \right)$wherein “N” is the length of the Zadoff-Chu sequence, “M” is a rootindex of the Zadoff-Chu sequence, and “n” is an index of each ofconstituent components of the sequence.
 12. The system of claim 11,wherein “N” is 63, the first index is 34, and the second index is 29.13. The system of claim 9, wherein the sequence is a P-SCH (Primary-SCH)transmission sequence.
 14. The system of claim 9, wherein the sequenceis generated in a frequency domain.
 15. A system, comprising: a receiverthat receives a radio signal from a network transmitter; and a processorthat detects a sequence in the radio signal, wherein the sequence isbased on a Zadoff-Chu sequence having an index in an index set, whereina sum of a first index and a second index in the index set correspondsto a length of the Zadoff-Chu sequence; wherein the system performssynchronization.
 16. The system of claim 15, wherein the processordetects the sequence using correlation operation.
 17. The system ofclaim 15, wherein the sequence is based on the following equation:$\exp \left( {{- i}\frac{M\; \pi \; {n\left( {n + 1} \right)}}{N}} \right)$wherein “N” is the length of the Zadoff-Chu sequence, “M” is a rootindex of the Zadoff-Chu sequence, and “n” is an index of each ofconstituent components of the sequence.
 18. The system of claim 17,wherein “N” is 63, the first index is 34, and the second index is 29.19. The system of claim 15, wherein the radio signal is a P-SCH(Primary-SCH) signal.
 20. The system of claim 15, wherein the index setfurther comprises a third index.